Crime Scene Investigation Philosophy, Practice, And Science Part 1

Crime Scene Investigation:Philosophy, Practice, and Science

Part One

Professor Robert C. ShalerPennsylvania State University

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Part One

Professor Robert C. Shaler

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Course Syllabus


Part One

About Your Professor.......................................................................................4

Introduction....................................................................................................5

Lecture 1 Introduction to Crime Scene Investigation...................................6

Lecture 2 The Crime Scene Investigative Paradigm andEvidence at the Scene ...............................................................12

Lecture 3 Bias, the Culture of Science, and the Scene Investigation...........19

Lecture 4 Scene Management: The Investigative Glue...............................25

Lecture 5 The Crime Scene Investigative Cascade,the Scientific Method, and Logic ...............................................32

Lecture 6 Origin of Evidence: Fundamental Principles of Evidence............37

Lecture 7 Macroscenes and Microscenes and FindingAssociated Evidence..................................................................43

Lecture 8 Searching: The Meat and Potatoes of the Investigation ..............51

Lecture 9 Scene Search Methods ..............................................................57

Lecture 10 Introduction to Forensic Archiving:Forensic Photography................................................................67

Lecture 11 Forensic Photographic Technique:Archiving Crime Types..............................................................76

Lecture 12 The Written Record: Case Files, Scene Sketches,and Worksheets ........................................................................84

Lecture 13 Sketch Types and Pinpointing Evidence at the Scene .................90

Lecture 14 Fingerprinting: The Intellectual Ingredients...............................97

Course Materials.........................................................................................102

Recorded Books ..........................................................................................104

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About Your Professor

Robert C. ShalerPhoto courtesy of R

obert C. Shaler

Robert C. Shaler is currently professor of biochemistry and molecular biol-ogy and director of the Forensic Science Program at Pennsylvania StateUniversity. He was the director of the Forensic Biology Department of theOffice of the Chief Medical Examiner (OCME) of New York City from 1990until his retirement in 2005.

As director, Shaler was responsible for the scientific and administrativeoperation of the Department of Forensic Biology in New York. He conceivedthe strategy for the DNA testing of family and World Trade Center (WTC)disaster samples for the identification of WTC victims. Shaler managed theWTC DNA victim identification effort, which included the OCMEDepartment of Forensic Biology, seven contract DNA testing laboratories,one public forensic laboratory, and three software vendors. He also estab-lished a crime scene reconstruction unit operating from within the medicalexaminer’s office. The unit responded to homicide crime scenes as sec-ondary responders called by the district attorney, the New York PoliceDepartment (NYPD), and the medical examiner. The unit, now called FARU(Forensic Analysis and Reconstruction Unit), still operates. Shaler was amember of the National Research Council (NRC) that authored the 2009report “Strengthening Forensic Science in the United States—A PathForward.” He was also on the NRC committee that authored the 2011report “Review of the Scientific Approaches Used During the FBI’sInvestigation of the 2001 Anthrax Letters.”

Professor Shaler’s areas of expertise include bloodstain analysis, crimescene investigation and reconstruction, footwear impressions, shootingscene reconstruction, and hit-and-run crime scene analysis.

Introduction

Crime scene investigation is an intellectual, scientific, and forensic inves-tigative exercise. Success requires experience, creative thinking, logic, andthe correct application of science and the scientific method. Scene investiga-tions, then, are intensely challenging intellectually. To disagree is ignorance,inexperience, or stupidity. As the legendary golf pro Bobby Jones is creditedwith saying about his profession, “Competitive golf is played mainly on afive-and-a-half-inch course . . . the space between your ears.” Competentcrime scene investigations are as cerebral an exercise as any scientific orinvestigative endeavor. They are comprehensive, tedious, exhausting, anddifficult. They are, in fact, a marriage of science and the art of investigation.

In 1995, former United States Attorney General Janet Reno made veryclear her position on how important crime scene investigation is in theDepartment of Justice publication Crime Scene Investigation—A Guide forLaw Enforcement.1

Actions taken at the outset of an investigation at a crime scene canplay a pivotal role in the resolution of a case. Careful, thorough inves-tigation is key to ensure that potential physical evidence is not taint-ed or destroyed or potential witnesses overlooked. While many agen-cies have programs in crime scene processing, the level of trainingand resources available varies from jurisdiction to jurisdiction, as doesthe opportunity to practice actual investigation.

1. Reno, Janet. Crime Scene Investigation—A Guide for Law Enforcement. Research Report.Washington, DC: U.S. Department of Justice Office of Justice Programs, 2000. P. iii.

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The Crime SceneThe investigation and analysis of the crime scene is the most critical partof solving a crime, because the scene commonly is believed to be the placewhere the crime takes place, and it is the only place where the participantsin the crime—the victims, the assailants, and the scenes—coincide in timeand space.

The French scientist Edmond Locard is credited with the statement that“every touch leaves a trace.” Simply, this means that an exchange of some-thing (for instance, physical evidence) takes place among the participants.Known as the Locard exchange principle, the transfer of evidence is theactive paradigm of criminalists and crime scene investigators as well as anessential ingredient of forensic investigations.

Who is responsible for investigating crime scenes? The most commonscene investigative paradigm has scene-trained police officers as theresponsible authority. Scientists, too, are often part of the investigatoryteam. Collectively, they are variably called crime scene investigators,forensic investigators, or technicians, depending on the jurisdiction inwhich they work. The term “crime scene technician” is inappropriate anddemeans the scientists and the specialized professional investigators whodo this work. The terms “scene scientist” and “scene investigator” aremore appropriate depending on the role each plays. If the person conduct-ing the investigation is a police officer or detective, a nonscientist, thisperson is considered a scene investigator. If the person is a scientist, thisperson is a scene scientist and may or may not be a scene investigator.

Consider the following as a first-blush attempt to define the crime scene:

The place where the participants of the crime meet in timeand space.

The definition includes the scene as a participant in the crime, whichmeans that the typical homicide scene involves the murderer, the scene, andthe victim. But all scenes are not this simple and might not adhere to such astrict definition. The dumped-body scenario involves several “scenes”: theplace where the murder took place, the transportation vehicle, and thedump location.

Lecture 1

Introduction to Crime Scene Investigation

The Suggested Reading for this lecture is Robert C. Shaler’s Crime SceneForensics: A Scientific Method Approach.

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What is the crime scene, and what role do forensics, forensic science,and criminalistics play in the crime scene investigative process?

During the anthrax mailings of 2001, the perpetrator mailed the lethalBacillus anthracis to his victims, which means the perpetrator was never inthe same location as the victim or the death location. This makes the“crime scene” elusive. A more comprehensive definition of the crime sceneis necessary to account for the more complicated distance scenarios.

The place where the participants meet in time and space or wherethe instrument of the crime (biological, explosive, or other) is pre-pared and delivered regardless of the route it takes.

Forensic Science

Sometimes the terms forensic science and criminalistics are used inter-changeably, and complicating this is a third term, “forensics,” that hasgained in popularity because of popular TV programs (for instance, “foren-sics units”).

Forensic scientist and professor at John Jay College of Criminal Justice Dr.Peter DeForest wrote the following:

The term forensic science is sometimes used as a synonym for crimi-nalistics. Both terms encompass a diverse range of activities.1

What DeForest says is certainly true, although he suggests the two terms maynot be synonymous, defining forensic science broadly to include criminalistics.

Forensic science is also defined in a broader sense to include forensicmedicine, odontology, anthropology, psychiatry, toxicology, questioneddocuments examination, and firearm and toolmark, and fingerprintexaminations, as well as criminalistics. Criminalistics is concernedwith the recognition, identification, individualization, and evaluationof physical evidence, using the methods of the natural sciences inmatters of legal significance.

The American Academy of Forensic Scientists (AAFS) is a group of physi-cians, lawyers, scientists, engineers, and other professionals divided into sec-tions under the broad umbrella called the forensic sciences.2 Interestingly,some of the sections in the AAFS are populated by nonscientists: jurispru-dence and forensic medicine being examples. Does that mean that forensicscience is simply an umbrella designation?

The National Institute of Justice categorizes eleven disciplines in the foren-sic sciences: general toxicology, firearms/toolmarks, questioned documents,trace evidence, controlled substances, biological/serology screening (includ-ing DNA analysis), fire debris/arson analysis, impression evidence, bloodpattern analysis (BPA), medicolegal death investigation, and digital evidence.Therefore, the following is a working definition of forensic science:

A diverse group of forensic professionals who employ and adhere tothe rigorous standards of their respective professions, who considermatters under consideration in order to ascertain the truth of a set ofalleged facts, criminal or civil.

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Criminalistics

As far as the AAFS is concerned, criminalistics is a subsection of theAcademy, each subsection a stand-alone profession. The Academy definescriminalistics as follows:

The analysis, comparison, and interpretation of physical evidence.The main role of the criminalist is to objectively apply the techniquesof the physical and natural sciences to examine physical evidence,thereby prove the existence of a crime or make connections.

This is an unsatisfactory definition and, to practicing criminalists, it mustdefy logic. Still, the definition trail becomes murkier. Inman and Rudin3

wrote that a scientist working in crime laboratories is “properly referred toas an analyst, a forensic scientist, or a criminalist.”

Their inclusion of an “analyst” is vague, and an analyst is not necessarily ascientist. A criminalist, however, is always a scientist.

Legal scholars also seem confused by the terms. University of Arizona pro-fessor Dr. Michael Saks lumps forensic scientists and criminalists togetherin his criticism of forensic science in his Individualization Fallacy.4

The term “criminalistics” was derived from the German kriminalistic andlikely coined by Hans Gross in the late 1800s to describe scientists workingon physical evidence in police laboratories at about the same time as theterm “police science” was becoming popular. The latter stuck, morphinginto “forensic science” in the twentieth century, while the former evokedonly confusion, sometimes becoming synonymous with a social science,criminology. In the late nineteenth century, scientific criminal investigatorswere known as criminologists. However, “criminalistics” neither died normorphed into criminology. Embracing Kirk’s philosophy, it became the pre-ferred term to describe scientists working in crime laboratories in Californiaand in a few laboratories in the eastern United States. Even today, civil ser-vice classifications for crime laboratory scientists are blurred. Some jurisdic-tions advertise job openings for forensic scientists and others for criminal-ists, seemingly equating the two.

The California Association of Criminalistics (CAC)5 definition of criminalis-tics is more appropriate than the AAFS’s and identifies criminalistics as aprofession while still defining what a criminalist does rather than what it is.

That professional occupation concerned with the scientific analysisand examination of physical evidence, its interpretation, and its pre-sentation in court. It involves the application of principles, tech-niques and methods of the physical sciences and has as its primaryobjective a determination of physical facts which may be significantin legal cases.

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Keith Inman and Norah Rudin attempt to clarify their position in the follow-ing statement.

This practical definition of criminalistics—the person who analyzes evi-dence in a crime laboratory may be referred to as an analyst, a forensicscientist or a criminalist—has taken on a life of its own, expanding toencompass a more general philosophy and cognitive framework.

This statement begins to clarify the essence of criminalistics. Criminalisticsis not simply a profession made up of scientists who examine evidence byemploying the principles of science and the scientific method. In fact, it isas much a science as it is a philosophy, a holistic approach with respect toan analytical strategy with results obtained and interpreted from within theframework of an entire case—that is, piecing together fragments of scientif-ic fact to eventually arrive at testable hypotheses.

Criminalists consider all the information in a case, not simply the analysisof a single piece of evidence. As such, criminalistics is an amalgam of theprinciples of science, logic, critical thinking, and experience. From this, aworking definition of criminalistics might be the following:

A profession comprised of scientists who embrace a holistic philoso-phy encompassing the principles of science, the scientific method,and logic with respect to the analysis of evidence and its relationshipto a set of alleged facts.

Forensics

The term forensics was inspired by popular TV programs, which is whythe public equates itwith forensic scienceand criminalistics.Still, forensics hasbecome an integralpart of the modernforensic lexicon.Clearly, though, thosewho practice forensicsin the TV sense arenot scientists and bydefinition cannot becriminalists or forensicscientists. Mostly, theyare police investigatorswho apply forensic sci-ence at crime scenesin order to locate andenhance evidence as

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© Robert C. Shaler

The diagram illustrates the essence of forensics. It is an all-encompassing term that embraces the categories and sub-disciplines of forensic science, such as those advanced bythe AAFS. Notice how criminalistics bridges the gapbetween the scientific and nonscientific aspects of crimescene investigation. Its role in the scene investigation iscaptured correctly.

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part of the scene investigation. Simply, the term forensics as discussedabove applies equally to lay professional investigators who process crimescenes and scene scientists. In this context, the following definitionmight suffice.

The application of standard investigative techniques to the processingof crime scenes by those police and/or scientific investigators skilledin the art.

The term has expanded, however, to include a broader category of forensicprofessions, and the following might be a more appropriate definition:

A broad term applied to professionals who apply accepted investiga-tive and/or scientific techniques to questions related to the criminal justice system.

In the evolving lexicon of everyday usage, even this might not suffice, asthe term forensics has attained an umbrella-like essence that seems tosupersede even that of forensic science. It might well be that “forensics”has become a term that encompasses all forensic activity, including forensicscience and criminalistics.

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FOR GREATER UNDERSTANDING

Questions1. Which of the following is best suited to investigate a crime scene?

a) forensic scientist c) laboratory scientistb) criminalist d) first officer on the scene

2. Differentiate between the three terms: criminalistics, forensic science,and forensics.

3. What is the name of the principle that describes the transfer of evidenceamong participants of a crime?

4. What is the AAFS?

5. According to the AAFS, what is the main role of the criminalist?

6. According to the California Association of Criminalistics, what is a criminalist?

7. The following was mentioned as a first-blush definition of the crime scene:“The place where the participants of the crime meet in time and space.”

a. Does this definition apply to terrorist scenes?

b. If your answer is yes, explain why. If your answer is no, explain why.

Suggested ReadingShaler, Robert C. Crime Scene Forensics: A Scientific Method Approach.New York: Taylor & Francis, 2011.

Other Books of InterestFisher, Barry A.J. Techniques of Crime Scene Investigation. 7th ed. BocaRaton, FL: CRC Press, LLC, 2004.

Saferstein, Richard. Criminalistics: An Introduction to Forensic Science.9th ed. Old Tappan, NJ: Pearson-Prentice Hall, 2004.

Lecture 1 Notes1. DeForest, Peter R., Henry C. Lee, and Robert E. Gaensslen. Forensic Science: An

Introduction to Criminalistics. Columbus, OH: McGraw-Hill Companies, 1983.

2. American Academy of Forensic Sciences — http://www.aafs.org/sections

3. Inman, Keith, and Norah Rudin. Principles and Practice of Criminalistics: The Profession ofForensic Science. Boca Raton, FL: CRC Press, 2000.

4. Saks, Michael J., and Jonathan J. Koehler. “The Individualization Fallacy in Forensic ScienceEvidence.” 2007. — http://works.bepress.com/michael_saks/1

5. California Association of Criminalistics. “What Is a Criminalist?” —http://www.cacnews.org/membership/criminalistics.shtml

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Why investigate the crime scene? There are five reasons, with locating evi-dence the by-product of the process.

1. Develop investigative leads for detectives.

2. Develop specific information—in the form of evidence or investiga-tive logic—to enable a successful prosecution.

3. Locate probative evidence, exculpatory or inculpatory, to provideevidence of innocence or guilt.

4. Locate significant information in the form of evidence to allow asuccessful and accurate reconstruction.

5. Link crimes through the evidence.

Who Should Investigate Scenes of Crimes?

Without question, modern crime scene investigation is a scientific endeav-or, but mixing science and investigators has not been widely popular oraccepted by police agencies, although that paradigm is slowly changing.

In these lectures, I am promoting the premise that the combined effortsof police investigators and crime scene scientists are critical in our tech-nologically expanding world of crime scene investigation. This applies notto only a single investigation but to a scene’s relatedness to other crimesof a similar nature or crimes of a dissimilar nature but committed by thesame perpetrator.

Crime Scene Paradigms: The Current Paradigm

Does a crime scene investigation paradigm exist? The answer is, sort of, although it is complex. A modern paradigm composite has two main elements:

1. Police secure, investigate, and assume responsibility for the integri-ty and security of the crime scene and its investigation.

Lecture 2

The Crime Scene Investigative Paradigmand Evidence at the Scene

The Suggested Reading for this lecture is Robert C. Shaler’s Crime SceneForensics: A Scientific Method Approach, chapter 1: “Crime SceneForensics: Philosophy, Practice, and Teaching.”

Is the current crime scene investigative paradigm appropriate for thefuture, considering that science is advancing almost exponentially? Andwhat is evidence? Is it always something tangible?

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2. Police document the scene and search for, preserve, and pack-age evidence, ensuring it reaches the appropriate individualsor agencies.

Most, if not all, crime scene investigations are more complicated than thatand individual scene investigative paradigms are prevalent. Because of fail-ures in scene investigations, it was realized that upgrading through stan-dardization of crime scene procedures was necessary. In the 1990s, theDepartment of Justice began publishing a series of pamphlets: DeathInvestigation—A Guide for the Scene Investigator (1996), Crime SceneInvestigation—A Guide for Law Enforcement (2000), A Guide forExplosion and Bombing Scene Investigation (2000), Fire and Arson SceneEvidence (2000), and Electronic Crime Scene Investigation (2001). In addi-tion, several books on the subject are available, as are numerous sceneinvestigative checklists. These references assume the police are the primescene investigators. Certainly, the result is an increase in the quality ofscene investigations. However, one can argue that upgrading has come at aprice: the repression of creative thought and logic, which leads to the sup-position that better scene investigations are possible.

Responders to crime scenes have varied experience, education, expertise,and resources. Most crime scenes are investigated by smaller agencies bysworn police officers having varied training and experience, likely fromlocal specialty workshops, the annual International Association ofIdentification (IAI) meetings, the FBI, or during police academy training atthe local level. Scene investigators in large cities have more experience andlikely more extensive training. In some jurisdictions, forensic scientistsrespond to scenes, especially violent crimes. In others, crime scene investi-gators call the crime laboratory for help in specific investigations.

An Evolving Scene Investigative Paradigm

Applicable science and technology are expanding exponentially and arebeing applied to scene investigations at what almost seems a feverish,uncontrolled pace. Current thought is that relevant information should beavailable as soon as possible so that the investigation can not only be con-cluded but that corollary investigations can be linked.

Before forming a modern scene investigative paradigm, it is important toconsider six arguable premises that embody the basis of a new paradigm.

Premise 1: Crime scene investigation is a scientific endeavor.

Premise 2: Performed correctly, a crime scene investigation is as difficultand as complex as any forensic endeavor.

Premise 3: Criminalists and experienced scene investigators should worktogether to interpret and draw inferences from scene data.

Premise 4: Lay investigators should not attempt to pattern match at sceneswithout the appropriate credentials.

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Premise 5: Certification should be mandatory. In addition, certificationshould be restructured so that scientific and police scene inves-tigators can be rigorously certified. Crime scene units should beaccredited and its individuals certified.

Premise 6: The investigation of the crime scene is the most critical part ofa competent forensic investigation.

A New Paradigm

Police training, however, is nonscientific and process-based, whichresults in a checklist approach to scene investigation. Still, the police are the keepers of the crime scene, and there is no question that theyare dedicated and take their work seriously. Police investigators havereal-world experience that is not taught in laboratories or universities.Criminalists should never replace scene investigators. If that happened,it would be a tragic loss of experience and expertise.

Unfortunately, many forensic scientists look at the scene investigation as amindless, nonscientific, and an almost rote process that should be practicedby those without a scientific background. They fail to realize that withoutthe proper application of the scientific method during the investigation, theevidence they receive in the forensic laboratory represents the bias of thescene investigators and that evidence left behind is lost forever.

Then what level of scientific expertise is necessary for scene investiga-tions? A new paradigm is necessary and should read something like this:

Police should control and assume the responsibility for the integrityand security of the crime scene. They should work cooperativelywith scene scientists who should lead the scientific aspects of thescene investigation. Together, they should search for, preserve, andpackage evidence and ensure that it reaches the appropriate individ-uals or agencies for subsequent analysis and interpretation by crimi-nalists and other forensic-related professionals. Together they shouldinterpret scene data as a basis for the logical reconstruction of thescene events.

The Concept of Evidence

Anyone studying crimes, forensic science, or crime scene investigationshould thoroughly understand the theoretical and conceptual basis of evi-dence. This is critical because evidence is the fundamental reason whycrime scenes are important. Interestingly, the authors of most of the widelyread texts on forensic science, crime scene investigation, and crime recon-struction fail to define evidence adequately. Retired laboratory director Dr.Richard Saferstein1 provides only a single sentence:

The examination of physical evidence by a forensic scientist is usuallyundertaken for identification or comparison.

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Dr. Suzanne Bell of West Virginia University defines physical evidence:2

Broadly speaking, any type of tangible evidence as opposed to some-thing such as the testimony of an eyewitness. Physical evidence canbe anything, from a microscopic trace of dust to a car, but there aresome generalizations that can be made. Physical evidence must bedocumented, collected, marked, transported, and stored in a mannerconsistent with its type.

The late medical forensic pathologist Dr. William Eckert3 differentiated tes-tamentary and demonstrative or physical evidence.

Demonstrative or physical evidence is something which may be seen,heard, touched, smelled, or tasted by the jury itself.

Forensic scientist Dr. Henry Lee4 considers evidence in the general sense,discussing the different types, their characteristics, and their importance,and offers readers no clear definition of what it is (emphasis added).

Physical evidence can be classified according to its physical state, bythe type of crime, by the nature of the evidence, by its composition,or by the types of question to be resolved (investigative question, notlegal question). Each of these classifications is useful for offering con-ceptual ideas and practical means in the crime scene search and anyother investigational assistance.

California forensic scientists Keith Inman and Dr. Norah Rudin5 introducethe concept of evidence, implying that evidence and any discussion about itis really a conversation about forensic science. Although they ask, “What isEvidence?,” they never offer an in-depth discussion except to consider that,

The law defines evidence only by its relevance.

This is an interesting statement because it considers the concept of evi-dence as something that has meaning while forcing it into a legal contextthat might not be entirely true. Retired U.S. Army Criminal InvestigationDivision General Ross M. Gardner6 defines evidence as,

. . . anything that tends to prove or disprove a fact in contention.

This thought is similar to Lee’s, who wrote more to the investigative ques-tion than Gardner, who seems to lean more toward the legal question.Gardner continues saying that, whether evidence is collected or not,

. . . it is real, it is tangible, and it cannot be denied. The physical evi-dence never lies. It is what it is, although we can certainly misinter-pret its meaning. . . . the concept of physical evidence tells a story.Each scene demands consideration of issues evident through observa-tions made by the investigator’s senses of sight, smell, and touch.Thus a complete consideration of physical evidence demands thatinvestigators be critically observant.

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To Gardner, evidence is related to the crimescene; however, he does hint at a psychologicalimplication during the scene investigative process:

. . . whether evidence is collected or not.

In the context of crime reconstruction,California forensic scientists W. Jerry Chisum andBrent Turvey coined the term “evidence dynam-ics,”7 which refers to anything that happens toevidence after it has been created at the scene.

. . . refers to any influence that adds, changes,relocates, obscures, contaminates, or obliter-ates physical evidence, regardless of intent.

Choosing the term, they state,

. . . all forms of physical evidence are at the mercy of environmentalchange, activity, and time.

These thoughts hint that evidence is more than something irrevocablyhaving a legal obligation.

Can evidence be defined so that the human psyche is able to recognize it?Can an investigator’s bias cause failure to recognize important evidencebecause it upsets a preconceived notion of what happened? What is aninvestigator’s skill at interpreting evidence at the scene, regardless of bias?

For example, an investigator locates an item at the crime scene, perhaps aknife lying a short distance from the deceased. He examines it visually forblood and, seeing none, decides the knife has no evidentiary value.

A second investigator conducting a second search of the scene also seesthe knife. She considers the wounds on the body, evaluates the relative sizeof the cuts in the victim’s shirt, and decides the knife might have probativevalue and collects it. She considers what she’s learned from experience,namely, that blood on a knife is not always readily apparent.

Critical decisions made at the crime scene to ignore or to recognize some-thing as evidence can spell the success or failure of an investigation. Thesame is true of the crime lab scientist. Where one forensic biologist mayexamine the knife visually and decide there is no blood present, anothermight examine the knife microscopically and then chemically and come upwith a different conclusion.

Evidence: The Legal Connection

Legal evidence differs from scientific evidence. The former requires alegal proceeding to determine whether it is evidence, defined by state andfederal rules that govern the admissibility into a legal proceeding.

Can evidence exist outside the boundaries of a legal proceeding or legallyrelated investigation? Eckert doesn’t believe so.8

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Thus physical evidence is always derivative of somesort of testimony.

But when does something become evidence? Whenan investigator perceives it as evidence, when it iscollected at the scene, or when it is introduced into alegal proceeding? The scene investigator believes it isevidence at the scene because it might have rele-vance for the legal proceeding. After being admitted,the importance of evidence’s value rises. This has adifferent “feel” than when it was still lying in a cor-ner at the crime scene waiting for an investigator to“see” it as evidence. However, once the scene inves-tigator does, and collects it, it begins its journey upthe ladder of evidentiary importance. First, it passesthe Locard and divisible matter tests, the investigator’srecognition test, the trial strategist’s test, and finally the admissibility stan-dard. It is then officially evidence.

Still, from an investigative perspective, evidence is in the mind of theinvestigator. If an analyst or investigator perceives something as unimpor-tant, even if documented correctly, it ceases to be evidence until another’sperception revives it.

What about evidence that is more of a thought or a hypothesis? Considerthe criminalist who attempts to reconstruct the events of a crime by exam-ining appropriate “evidence.” Much of what is examined is tangible, butthe thought process is not. However, in court, these thoughts become opin-ions, which can be admissible. The thoughts or opinions are evidence,though not real or tangible.

Therefore, a working definition of evidence might be the following:

Anything associated with a crime scene, incident, or argument;whether or not it has been collected, described, photographed, analyzed scientifically or reasoned about, and which might be introduced into a legal proceeding in order to ascertain the truth of an issue.

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Questions1. Name five reasons for investigating a crime scene.

2. What is the current crime scene investigative paradigm?

3. Considering our contemporary society, name two reasons why this par-adigm is doomed to fail as more science and technology are used atcrime scenes.

4. Name two types of evidence.

5. Explain the difference between perceived evidence at the scene toadmitted evidence in a legal proceeding.


Other Books of InterestChisum, W. Jerry, and Brent E. Turvey, eds. Crime Reconstruction.Burlington, MA: Academic Press, 2007.

Fisher, Barry A.J. Techniques of Crime Scene Investigation. 7th ed. BocaRaton, FL: CRC Press, LLC, 2004.

Geberth, Vernon J. Practical Homicide Investigation: Tactics, Procedures,and Forensic Techniques. 4th ed. Boca Raton, FL: CRC Press, 2006.

Inman, Keith, and Norah Rudin. Principles and Practice of Criminalistics:The Profession of Forensic Science. Boca Raton, FL: CRC Press, 2000.

Lecture 2 Notes1. Saferstein, Richard. Criminalistics: An Introduction to Forensic Science. 9th ed. Old

Tappan, NJ: Pearson-Prentice Hall, 2009.

2. Bell, Suzanne. Encyclopedia of Forensic Science. 2nd ed. New York: Facts on File, 2008.

3. Eckert, William G. Introduction to Forensic Sciences. 2nd ed. Boca Raton, FL: CRC Press,LLC, 1997.

4. Lee, Henry C., Timothy Palmbach, and Marilyn T. Miller. Henry Lee’s Crime SceneHandbook. Burlington, MA: Academic Press, 2001.

5. Inman, Keith, and Norah Rudin. Principles and Practice of Criminalistics: The Profession of Forensic Science. Boca Raton, FL: CRC Press, 2000.

6. Gardner, Ross M. Practical Crime Scene Processing and Investigation. Boca Raton, FL: CRCPress, 2005.

7. Chisum, W. Jerry, and Brent E. Turvey. “Evidence Dynamics: Locard’s Exchange Principleand Crime Reconstruction.” The Journal of Behavioral Profiling. 2000 1(1).

8. Eckert, William G. Introduction to Forensic Sciences. 2nd ed. Boca Raton, FL: CRC Press,LLC, 1997.

What is the scientific method and what role, if any, does it play incrime scene investigations? Can the scientific method mitigate bias incontemporary crime scene investigations?

The hallmark of any successful crime scene investigation is a team effortwhose director, like the maestro of an orchestra, is its leader. How well theteam performs is related to how well its leader employs the scientificmethod, thinks critically and creatively, opens lines of communication withsubordinates, and employs inductive, deductive, and abductive logic. Ifdone properly, the culture of science protects the team from making criticalmistakes because science itself is self-correcting. Mistakes, when found, arecorrected, and biases, through the team effort and the application of the sci-entific method, are avoided.

The Scientific Method: Scene Scientists and Scene Investigators

Science students will recognize the following widely accepted list for thescientific method:

• Observe a phenomenon that has no good explanation.

• Formulate a hypothesis.

• Design experiments to test the hypothesis.

• Perform the experiments.

• Accept, reject, or modify the hypothesis.

All scenes have multiple gross observable phenomena, some of whichmight have no immediate, simple, reasonable or logical explanation.Each might also have many explanations of which only one rests in theground truth. Frustratingly, most explanations will never be known withabsolute certainty, because the investigators were not present when theevent took place.

Observable phenomena can be put into categories such as the following:

• People living their lives.

• Activity of the crime that spawned the investigation.

• Activity or events unrelated to either of the above.

• Unknown at this time.

Lecture 3

Bias, the Culture of Science, and the Scene Investigation

The Suggested Reading for this lecture is Robert C. Shaler’s Crime SceneForensics: A Scientific Method Approach, chapter 2: “The ScientificMethod, Bias and Reasoning.”

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Observable phenomena must be interpreted correctly, which means plac-ing it into the correct category. If these phenomena are misinterpreted,the result can be a botched investigation leading to the arrest and convic-tion of an innocent person. Using experience to interpret new phenome-na is a normal extension of an engaged mind, and it is reasonable. It is,however, the seed of experienced-based bias, the natural consequence ofliving and working in the real world. I called it the “I’ve seen it a milliontimes” syndrome, because everyone pigeonholes experiences. The resultis a mixture of correct and incorrect interpretations of the scene.

Scene investigators trust their experience and draw final conclusions basedon their observations over time. This seems reasonable, but the processautomatically puts the brakes on the mental exercise when they’ve “decid-ed” what happened. The scene scientist never proffers a “final” interpreta-tion or conclusion until all hypotheses have been “tested” and alternativeexplanations exhausted. The word “final” is in quotes because even then aconclusion can change if new evidence is located. It is this “testing” of alter-nate explanations that separates scene investigators from scene scientists.

The best fact-fit can only be determined through experimentation, whichdoes not necessarily imply laboratory experiments, although that is a possi-bility. Some experimentation could be done at the scene, which mightchange the hypotheses or create new ones. Laboratory testing done on evi-dence collected is usually necessary, and that can also change hypotheses.

The scientific method is not just a checklist but a method for disprovingthe original or alternative hypotheses. This not-so-subtle fact is lost on mostlay investigators.

After the data have been analyzed, hypotheses tested and retested, a pointcomes when more testing seems unnecessary, and a truth of some sortemerges. This truth may not represent the actual ground truth, but it willbe closer to reality than if the process had been stopped after the first set ofhypotheses. The process may have led to new evidence that should haveelicited additional questions and perhaps new hypotheses.

The scientific method is the only way to eliminate bias in an arena wherethere are few, if any, checks and balances. For scene investigators, the sci-entific method is not satisfying because it offers only a sketchy roadmap ofhow to conduct a competent scene investigation. This is its reality.Scientific processes are complex, and so too are scene investigations.

At the crime scene, the scene scientist conducts the business of science dis-tinct from the investigative role of the police scene investigator. The scientif-ic mind places a premium on precision, objectivity, repeatability, experimen-tation, uncertainty management, peer review, and experience to arrive atreliable interpretations of clues left at the scene. The scene scientist has nomission or allegiance except to the facts. The scene investigator’s mindsearches for facts (evidence) to fit a scenario or an “idea” of what happened

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based on experience or on information relayed by messengers (for example,witnesses or other officers). Regardless, they play on the same team.

Bias in Scene Investigations

While everyone is saddled with biases,1 investigators would probably bristleat the suggestion that they are biased. They correctly believe crime sceneinvestigation is a critical process and, as such, they strive to find evidenceto support a successful prosecution. They would also challenge the sugges-tion that they do not actively search for exculpa tory evidence because theirsubconscious minds are focused on prosecutions. Scene investigators in theUnited States mostly represent the investigative arm of law enforcementand, thus, are part and parcel of the prosecution team. By definition, then,their mission is to find probative evidence to prove someone committed thecrime. They do this through a process of deductive reasoning where, if thepremises are true, the conclusions must also be true. By definition, then,they are as biased as the crime scene expert hired by the defense team.

The prosecutor is the most critical member of the prosecution’s adversari-al team and, by definition, is biased. But the prosecutor, as an advocate, issupposed to be biased; so is the defense attorney. The scene scientist whoresponds to the scene and who is likely employed by the prosecution’steam must resist the inherent biases and should have no stake in theinvestigative process. Science brings objectivity to the investigativeprocess. Science encourages cautious, precise statements and frowns onstatements that venture beyond facts.

An example of the kind of bias to which investigators and scene scientistsfall prey includes what is known as the bandwagon effect, which is the ten-dency to do or believe things because many other people do. A forensicexample would be the prosecutor or detective who is certain that a suspectis the killer because he is a “bad guy.” Letting the crime scene investigatorknow this could sway the course of the scene investigation, especially if thescene investigator knows who the “bad guy” is. Another example is what isknown as confirmation bias. This is the tendency to search for or interpretinformation in a way that confirms one’s preconceptions.

Uncertainty is the breeding ground for bias, and two factors are at work:ambiguity and subjectivity.2, 3 In the former, if the evidence or the circum-stance is incomplete, murky, or equivocal, the scene scientist or the crimescene investigator is free to develop opinions, which can represent the ana-lyst’s personal bias. When subjectivity is the issue, scene interpretationsrest on an examiner’s experience or beliefs, which results in bias.

How does one integrate the self-correcting aspect of science into thescene investigation process? Science does it by challenging hypothesesdeveloped via the scientific method and by peer review. Challenging inves-tigative hypotheses at a crime scene is difficult because scene investigatorsare usually from the same agency, and challenging a hypothesis may

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require challenging a supervisor. This can be professional suicide. Theideal is a team leader who is willing and open to having intellectual discus-sions concerning alternative hypotheses during the investigation.Theoretically, this ideal is certainly possible.

A scientist working with the team will change the dynamic of the team’spersonality, because a scientific presence brings a sense of objectivity. Therecan be personality conflicts and differences in authority, but the scientistwould not be the team leader’s subordinate. Subordinate team membersmight feel apprehensive about challenging their superior, but the scientistshould not.

Reasoning: Deductive and InductiveA form of reasoning takes place during any crime scene investigation. Andsince crime scene investigation is the direct application of the scientificmethod, there must be logic and reasoning.

Deductive reasoning works from the general to the more specific and isoften referred to as a “top-down” process of logic. It begins with a theoryand moves to a testable hypothesis. Testing or verification requires observa-tions or experiments that address the hypothesis, which is ultimately eitherconfirmed or not. This feels like what happens at crime scenes.

Inductive reasoning begins with an observation and moves to a testable ten-tative hypothesis. This is how scientists reason and it also feels like whathappens at the crime scene. From there, a theory is derived, which must beconfirmed. It moves from thespecific to the general and isthought of as a “bottom up”process of logic or reasoning.

Crime scene investigationsrequire both types of reasoningsimultaneously. And by examin-ing Figure 3.1, it appears thatoverlap exists, which means itmight be possible to assembleboth into a singular concept thatcontinuously cycles from theo-ries to observations and backagain to theories. In fact,researchers often observe pat-terns in data that lead to thedevelopment of new theories—an inductive process. All divi-sions of natural science employinductive reasoning and estab-lish theories and laws of nature

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Figure 3.1:Deductive and Inductive Reasoning

based on observation and ondeductive reasoning to draw con-clusions. There are circumstanceswhere observations come first (forexample, the crime scene). Onemight observe certain facts thatform a pattern that eventuallyleads to tentative hypotheses,which are tested to form the basisof a theory. Still, the theory mustbe confirmed, which would beabduction (see Figure 3.2).

Many believe the process of rea-soning during crime scene investi-gation is intuitive and subject toexperience. Reasoning isemployed but likely not as a con-scious thought process. The scien-tist does this as a matter of education, training, and experience. Likewise,good investigators do it as a matter of intuition, training, and experience.

As Sherlock Holmes said,

In solving a problem of this sort, the grand thing is to be able to rea-son backward. That is a very useful accomplishment, and a very easyone, but people do not practice it much. In the everyday affairs of lifeit is more useful to reason forward, and so the other comes to beneglected. There are fifty who can reason synthetically for one whocan reason analytically.

Figure 3.2:Inductive/Deductive/AbductiveReasoning as Employed inCrime Scene Investigations

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Questions1. List the steps of the scientific method.

2. What is bias?

3. Give an everyday example of confirmation bias.

4. How do deductive and inductive processes differ?


Other Books of InterestChisum, W. Jerry, and Brent E. Turvey, eds. Crime Reconstruction.Burlington, MA: Academic Press, 2007.

Lecture 3 Notes1. Dror, Itiel, and R. Rosenthal. “Meta-Analytically Quantifying Reliability and Biasability of

Forensic Experts.” Forensic Science. Vol. 53(4), 2008, pp. 900–903.

2. Cooley, Craig M., and Brent E. Turvey. Chapter 3: “Observer Effects and Examiner Bias.”Crime Reconstruction. Eds. W. Jerry Chisum and Brent E. Turvey. Burlington, MA: Elsevier,pages 58–60.

3. Phillips, V.L., and Michael Saks. “The Application of Signal Detection Theory to DecisionMaking in Forensic Science.” Forensic Science. Vol. 46. 2001, pp. 294–298.

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Managing a crime scene is a critical skill. A successful team leader/manag-er must possess certain qualities: broad experience in scene investigation,knowledge of scene forensics/criminalistics, knowledge of police and legalprocedures, understanding the value of physical evidence, knowing the lim-itations of the science, applying the scientific method, recognizing, collect-ing, and preserving evidence, and knowing how to effectively blend theinvestigative sequence into a cohesive operation.

The contemporary scene manager must demonstrate leadership skills towork efficiently in an intense environment that typically might be consid-ered ordered chaos. The scene manager is someone who can multitask,work well with people, and understand the intricacies of the investigationand its ancillary activities.

The management philosophy I present is taken from personal experienceand from the experience of others who have written about scene manage-ment. However, it is mostly based on the management process presented byGardner1 and enhanced with the scientific method. The format is based onthe U.S. Army model, which is a roadmap on how to manage an investiga-tion from a procedural perspective. The hallmark of the process is a seriesof checks and rechecks designed to ensure that nothing is overlooked.

Scene management cannot be done properly without practice because it isas much vocational as theoretical. Managing a scene is dictated by the spe-cific case circumstances. Many might even argue that scene management is

Lecture 4

Scene Management: The Investigative Glue

The Suggested Reading for this lecture is Robert C. Shaler’s Crime SceneForensics: A Scientific Method Approach, chapter 3: “Management: TheInvestigative Glue.”

The first officer at the crime scene has important responsibilities. Whatare they, and how do they relate to the subsequent investigation by thecrime scene unit? Why is the scene management the glue that holds theinvestigation together?

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entirely vocational, which might have been true until sophisticated scienceand technology became an integral part of the process.

Scene management begins with a first or responding officer, an official whois probably not a member of the crime scene team. Because he or she isusually the first official there, the first responder’s role is critical to a suc-cessful investigation.

The Responding OfficerThe first official on the scene has critical responsibilities that can dramati-cally affect the subsequent scene investigation. These responsibilities areoutlined in a National Institute of Justice pamphlet, “The First Officer’sResponsibilities.”2 Without going into exhaustive detail, a first officer’sresponsibilities can be placed into discrete categories of observations,actions taken, and documentation.

First Responder ObservationsGenerally, observations lead to a documentable action. Such first-levelobservations require the first responder to answer certain mental questionsfor the investigation to proceed smoothly. Among others, these shouldinclude, What happened here and who should respond? The answers comefrom responses to other questions:

• Is the scene active—is the perpetrator on the scene?

• Is the scene clear?

• Are victims injured or alive?

• Are there witnesses?

A determination of the scope of the scene is necessary: Is this an indoor-only crime or does it have an outdoor component? Even in indoor scenes(for example, a homicide), the perpetrator entered the scene somehow.

Second-level observations reflect specifics and include subtle details that areobvious only after entering the scene. These, like all observations, should bearchived using a digital or tape-recording device or a notepad. The digital erahas elevated the potential for rapid information gathering. Point-and-shootcameras are readily available and are capable of providing important as-the-scene-was-first-seen information. These photographs can archive impressionsand observations. Although these cameras are capable of giving fairly high-resolution photographs and are certainly helpful, they are not a substitute forthe subsequent official archiving done by the crime scene unit. The first offi-cer must be cognizant of and immortalize the following.

Fleeting evidence Entry/exit pointsOdors: cooking, gunshot, Doors: locked/unlocked,cigarette/cigar smoke indications of tamperingMelting ice cubes Windows: locked/unlocked,

indications of tampering

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Signs of activity Date/time indicatorsStruggle NewspapersTV/radio on Stopped clocksMeals: dishes in the sink Spoiled foodFood on the table Hot/cold itemsPartially eaten food Wet blood

Objects moved Monitor evidence moved/alteredAccounting for moved such as by EMTs as they attendor out of place to living victimsobjects (furniture)

Protecting obvious critical evidenceFingerprints on dusty surfaces or dry residueprints on the floor or furniture Cartridge casesSpent bulletsWet and dry residue footwear impressionsBroken glass

First Responder Actions

If the scene is active, that is, a suspect/perpetrator is still there, theresponding officer will require police backup. If people are wandering in andout of the scene, they must be removed and taken to separate locations andtheir contact information obtained. Ideally, they will remain in a sequesteredarea to answer questions. Live victims may require medical attention. Thefirst responder must call emergency medical services. If there are deceasedindividuals, the medical examiner should be called.

Witnesses can also be suspects. They must be segregated and separatedfrom other witnesses so that they cannot exchange information. Potentialsuspects should be detained and their contact information obtained.

There should be a hands-off policy at the scene. This means beingextremely diligent to ensure that evidence is not compromised, damaged,or destroyed.

The following are possible considerations for indoor scenes:

• Establish scene boundaries

• Protect possible entrance/egress points

• Protect possible probative evidence or evidence location points

For outdoor scenes, a short list might include the following:

• Protect entrance/exit points

• Be cognizant of weather restrictions

• Cordon off large areas and get help from others

The media is also a concern, and they should be moved far enough fromthe scene so that sophisticated listening devices cannot tune into discus-sions among investigators, or so that cameras with powerful lenses cannotcapture salacious material. The investigation does not need dead bodiesending up on the evening news. A general schematic of a hypotheticalscene is shown in Figure 4.1.3

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Level 1 restricts access to the scene by the general public and the media.Notice that the media has been sequestered to a specific area that is nearbut not too close. The media understands that they are free to move any-where and photograph from where it pleases in areas that are not specifical-ly designated as part of the crime scene. Barrier tape is critical, and if themedia crosses it, they risk arrest and confiscation of their equipment.Witnesses are segregated from investigators, the media, and each other.Eyewitness accounts are notoriously inaccurate, and having witnesses com-paring notes is not in the best interests of the investigation.

Level 2 is designated for officials involved in the investigation. Only lawenforcement, other officials, and dignitaries are permitted access to thescene and are permitted inside this area. This area should be marked ordesignated specifically by the first officer, with the understanding that theseboundaries are subject to change by the investigators in charge. Ideally, acommand center would be in Level 2, where the crime scene unit sets upits equipment and packaging areas. It can be outside the target area, whichis where the crime took place.

When the detective in charge of the investigation takes over, the finalresponsibility of the responding officer is to debrief the investigator and toconduct what is known as the “walkthrough.” This is when the respondingofficer and the investigator examine the scene together and exchange criti-cal information and control. The responding officer points out observationsmade, important details of the scene, and other thoughts, impressions,observations, details, photographs, notes, recordings, and so on.

Figure 4.1: Scene Security: Schematic of Security Levels

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First Responder Documentation

The first responder must document everything discussed above. Whetherthe information is recorded with an audio recorder or written in a note-book is not important. Most important is that information is not trusted tomemory, which in time would be lost to the investigation.

The Team Manager/Leader: Managing the Scene Investigation

After the official transfer of scene control, the systematic, logical, and ana-lytical process of ascertaining what the scene has to offer in evidentiaryterms begins. This is when the team leader takes charge of the investiga-tion. This individual understands that no one person does it all and that thesuccessful scene investigation is a team endeavor determined by the sceneitself and the resources available.

Most crime scene units include police officers trained to process crimescenes. Sometimes additional expertise is required, and adjunct or part-timemembers of the unit will be contacted on an as-needed basis. For example,if bones are uncovered, an anthropologist will be called. If decomposingbodies are found, a forensic entomologist might be needed.

Crime scene units having large caseloads or scarce resources may assign asfew as two or three investigators to each scene. From any reasonable per-spective, two-unit crime scene teams lack the expertise and efficiency to dojustice to most scenes, and they run the risk of missing critical evidence.

Although armed with the first responder’s information, the team leadershould never assume that everything has been completed or even begun. Itmight be that this was the responding officer’s first homicide scene, andinexperience and emotional trauma can be expected to lead to mental laps-es. Double checking is essential. During the debriefing, the team leadermust consider legal issues for entering the scene, because no scene investi-gation can begin until the legal process is complete.

At this point, the team leader must complete preliminary work that hadnot been done. For example, if the responding officer neglected or did nothave time to set aside space for the command center, the team leader mustconsider where it should be. Perhaps the walkthrough led the team leaderto believe the command center should be moved. The same holds true forthe media. These are important considerations. The team must be able towork in an area that is close to the main scene activity but not in an areawhere evidence could be destroyed.

The team leader must consider anything that can interfere with the effi-cient processing of the scene. Time constraints should be evaluated careful-ly. Consider a hit-and-run on a major roadway. Blocking a road for anextended time might be impossible. A homicide in the woods where rain orsnow is forecast will force the team leader to consider protecting fragile evi-dence more than usual.

All this occurs before the team sets foot inside the scene. There are alsospecific scene processing responsibilities to coordinate. Scene activity mustbe completed in a reasonable timeframe and done correctly.

The team leader will be coordinating the activity of the team, workingwith detectives investigating the crime and the medical examiner. Thereshould be a continuous exchange of information. From a scene perspective,the investigation begins when the team leader designs an investigative planand strategy. This includes the how, who, and when of the typical activitiestaking place: archiving, searching, collecting, packaging, and so on. Duringthis activity, the team leader tracks the progress of the investigation andensures that the work is done correctly. In addition, the team leader shouldbe thinking about how to wrap up the investigation, put together the casefile, and then write the investigative report.

1–3–1 Sub-Teams

Without doubt, certain activities should take place before others. Forexample, fragile evidence should be marked and protected and/or collectedbefore much activity takes place. For the work to be done efficiently, theteam leader needs to create sub-teams.

Sub-teams can have one or more members. For example, a one-member sub-team might be an individual who does the establishing (overview) photogra-phy and video. A second sub-team might have two members who sketch,while a third one-member sub-team might search for evidence. As the scenework progresses, the responsibilities of sub-teams and possibly their composi-tion can change. Most sub-teams do double-duty to complete the necessarytasks, this represents a scheduling problem for the team leader.

The composition of the crime scene unit and its sub-teams is determinedby the resources available. At no time should a team member be standingaround with nothing to do. All scene investigations have tedious moments,exacting times, and busy work to do. There are also times when it is neces-sary to wait for a task to be completed before moving into an area.Generally, though, there is a lot to do and little down time. It is the teamleader’s responsibility to keep the team members busy and focused.

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Questions1. List the credentials of an effective crime scene manager/team leader.

2. List five responsibilities of the responding/first officer on the scene.

3. What should the first responder not do?

4. Why is it necessary to segregate witnesses?

5. Why is it necessary to limit access to the scene?


Other Books of InterestFish, Jacqueline T., Larry S. Miller, and Michael C. Braswell. Chapter 2:“The First Response.” Crime Scene Investigation. Bethesda, MD:LexisNexis/Anderson Publishing, 2007.

Gardner, Ross M. Practical Crime Scene Processing and Investigation. BocaRaton, FL: CRC Press, 2007.

Lecture 4 Notes1. Gardner, Ross M. Practical Crime Scene Processing and Investigation. Chapter 4: “ProcessingMethodology.” Pp. 75–86. Boca Raton, FL: CRC Press, 2004.

2. National Institute of Justice. “The First Officer’s Responsibilities,” 1995.

3. Adapted from Lee, Henry C., Timothy Palmbach, and Marilyn T. Miller. Henry Lee’s CrimeScene Handbook. Chapter 3. Pp. 49–70. Burlington, MA: Elsevier Academic Press, 2005.

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Lecture 5

The Crime Scene Investigative Cascade,the Scientific Method, and Logic

The Suggested Reading for this lecture is Robert C. Shaler’s Crime SceneForensics: A Scientific Method Approach, chapter 3: “Management: TheInvestigative Glue.”

The crime scene investigative cascade by itself is an inappropriatestand-alone investigative tool. Marrying it with the scientific methodelevates the cascade to a higher investigative potential.

The team leader determines the team’s scene investigative strategy. Crimescene work is daunting and tedious, and keeping track of multiple simulta-neous activities can be overwhelming. The goal of locating and collecting allof the probative evidence may seem like a simple task, but it is not.

The investigative work takes place in logical steps so that probative evi-dence is not missed, damaged, or obliterated. And completing an initialscene investigation is no guarantee that the work is finished. It is notunusual for a crime scene unit to revisit a scene several times. Even after ascene is released, questions can still arise, and additional theories are some-times proffered that question the original investigation.

The general sequence of a scene investigation is shown in Table 5.1.*Novice investigators often attempt to complete the “mundane” archivingchores quickly to begin the fun stuff: fingerprinting, electrostatic lifting ofdust prints, and enhancing bloodstains. They quickly realize, however, thatan overanxious investigator makes stupid, sometimes irrevocable, mistakes,and that the best approach is slow and easy.

The four steps (preprocessing, visual inspection, first touch, and secondtouch) illustrate the general sequence or stages of the investigation. Theonly exception to not touching during the first two stages concerns fragileevidence (for example, dust prints and cartridge cases) that must be protect-ed and collected as soon as possible.

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Crime scene investigative work is a cascade of sequential events. Prepro -cessing occurs before the crime scene unit members set eyes or feet insidethe scene. This critical step is essentially the responding officer turning thescene over to the team leader. After preprocessing, the team leader has tomake several critical decisions, some of which might require a meeting withthe crime scene team. Assuming the team has the legal right to begin theinvestigation, the first order of business is to categorize the scene: homicide,sexual assault, burglary, hit-and-run, mass fatality, or other theme.

The Crime Scene Investigative Cascade

The first major activity is Visual Inspection (see Figure 5.1); only visualobservations are made that become translated into future action. Here, thescene is archived. The three balloons labeled Observations, Video/Photo-graphy, and Sketching illustrate the major activities taking place. All observa-tions should be listed on a notepad or into a digital recorder. Archiving pho-tographically includes the three basics of forensic photography, to be dis-cussed later, although most midrange and close-up photography will be takenduring other phases of the investigation. The box labeled First Recheck is acritical reassessment of what has been accomplished. Here, a sub-team orthe team leader checks to see what might have been missed. Evidence thathad been missed must be documented as though being catalogued for thefirst time. At the conclusion of the visual phase the first aspects of archiving,establishing photography, and sketching should be complete.

The next step is labeled First Touch to emphasize that this is the first timehands actually touch anything at the scene. In this phase, the team mightrelease the body, but only after the medical examiner has examined it andthe team has considered it as a scene unto itself (for example, archiving,

Table 5.1: Generalized Scene Investigative Sequence

Phase 1Preprocessing Visual First Touch Second Touch

Legal issues Observable Body release Chemistry:phenomena Fingerprints/

footwearimpressions

Debrief First Archiving: Evidence Third recheckResponder Establishing collection

photography

Victim care (alive) Archiving: Second Beyond orMedical Examiner Sketching recheck outside thecalled immediate scene

First walkthrough First recheck Wrap-up:Debrief team

gunshot residue, or bloodstain pattern analysis). In First Touch, sub-teamsare busy performing multiple tasks, such as dusting and lifting fingerprintson walls and other surfaces; another sub-team might be examiningshoeprints to determine whether they are dry or wet in origin, and theteam leader might be moving furniture to search for other evidence.Midrange and close-up photographs document these activities. New evi-dence must be documented, marked, collected, and packaged. Finally, aSecond Recheck performs a second critical review of the team’s activity.After the Second Recheck, the investigation is working toward finishing.

In the Second Touch phase, chemical enhancements of evidence takeplace on items that cannot be removed from the scene. This might includeenhancing bloodstains, Super Glue fuming fingerprints, bullet path determi-nations, or gunshot residue identification. These activities are the last inthe sequence because the associated evidence is generally not fragile andwill not be obliterated or destroyed during the previous scene activity.

After completing the chemical phase, the team does the Third Recheck, thefinal review. The balloon labeled Beyond is a reminder that crime scenes arenot necessarily relegated to the place where a body was found. It should beexpected that some activity took place outside the set boundaries of the

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Figure 5.1: The Scene Investigative Sequence:Overview

scene; someone had to get into the scene to commit the crime. The drive-way might have tire tracks, or fingerprints could be on windowsills. Thismeans investigating the boundaries of the surrounding area as though theywere independent scenes. After the Third Recheck, the team wraps up theinvestigation, and the team leader begins thinking about releasing the scene.

Integrating the Scientific Method

Integrating the scientific method and the criminalistic approach into thestep-by-step process ensures that an investigation is successful. As it standsin the scene processing cascade, there is only a hint of such a feedbackmechanism embodied as the First, Second, and Third Rechecks. Doubtless,investigators exhibit reason and logic, but the rechecks are observationalchecks to ensure that nothing has been missed. This is a good approach,but, alone, it is insufficient.

However, marrying the cascade with criminalistic logic automaticallyembraces the scientific method. Thus the recheck steps in the scene pro-cessing cascade, if they embody hypothesis testing, rejection, etc. will pro-tect the investigation from mistakes.

The scientific method is the foundation of any investigation. Adding thescientific method to the scene processing cascade upgrades the three re-checks to a time-tested, scientific process, which could translate into four,ten, or more “rechecks” as new hypotheses develop.

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Questions1. List the four general stages of a competent crime scene investigation.

2. What is meant by the phrase, “Scene Processing Cascade”?

3. After preprocessing, what is the hallmark of the next phase of the investigation?

4. Why does marrying the scene processing cascade with the scientificmethod upgrade the quality of the investigation?

5. What does the term “beyond” mean in the Second Touch part of thescene processing cascade?


Other Books of InterestGardner, Ross M. Practical Crime Scene Processing and Investigation. BocaRaton, FL: CRC Press, 2007.

Lecture 5 Notes*Gardner, Ross M. Practical Crime Scene Processing and Investigation. Chapter 4: “ProcessingMethodology.” Pp. 75–86. Boca Raton, FL: CRC Press, 2004.

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The Locard Exchange Principle: “Every Touch Leaves a Trace”

Any meaningful discussion of crime scene evidence must begin withFrench physician and lawyer Dr. Edmond Locard. His work and philosophyembody the phrase attributed to him, “Every touch leaves a trace.”Although Locard probably never said it precisely like that, the exchangeprinciple ascribed to him forms the basic philosophy of and the reason forconducting a crime scene investigation. Locard’s writings never explicitlymentioned something that he termed an exchange principle, but he did cer-tainly embrace the concept of a transfer of evidence.

Locard was convinced that microscopic evidence formed the essence ofevidence transfer. As the forensic microscopist Richard Bisbing wrote,1

I commonly express the principle this way: whenever two objectscome in contact with each other, they transfer material from one tothe other. The Locard exchange produces the trace evidence of inter-est from fingermarks to mud.

Perhaps surprisingly, Locard attributes his revelation with respect to traceevidence’s importance in criminal investigation to two seemingly divergenthistorical figures.2

I must confess that if, in thepolice laboratory of Lyon, weare interested in any unusualway in this problem of dust, itis because of having absorbedthe ideas found in Gross andin Conan Doyle. . . .

Lecture 6

Origin of Evidence: Fundamental Principles of Evidence

The Suggested Reading for this lecture is Robert C. Shaler’s Crime Scene Forensics: A Scientific Method Approach, chapter 4: “The Fundamental Principles of Evidence.”

The fundamental principles of forensic science and of crime sceneinvestigators are the Locard exchange principle and the principle ofdivisible evidence.

Dr. Edmond Locard (1877–1966) and hisson in the Lyon crime laboratory, ca. 1910.Locard produced a seven-volume work,Traité de Criminalistique, and in 1918, he developed twelve matching points for fingerprint identification.

© City of Lyon, France

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Hans Gross was a forensic giant, so it is little surprise that Locard studiedGross’s 1893 Handbook for Examining Magistrates,3 which formed thebasis of modern criminalistics. This was the first publication describing the marriage among science, the crime scene investigation, and the law.

Locard’s second expressed influence was Sir Arthur Conan Doyle, a Univer -sity of Edinburgh-educated physician who learned analytical reasoning fromhis professor Joseph Bell, an army surgeon and hospital physician. Doyle skill-fully applied his medical training and acute mind to create the fictionalSherlock Holmes, a highly egocentric yet contemplative master scientificsleuth. As Locard wrote,4

For in the adventures of Sherlock Holmes, the detective is repeatedlyasked to diagnose the origin of a speck of mud, which is nothing butmoist dust.

Gross and Doyle, as well as the German scientist Liebig, were not the onlywell-known forensic investigators—“criminologists” at the time—whomight have influenced Locard. An early association in Lyon was a heavy-weight criminologist in the early 1900s, Alexandre Lacassagne, the founderof the Lacassagne School of Criminology and a major force in criminalinvestigations in Lyon.

After passing the bar exam in 1907, Locard traveled to Paris to study withAlphonse Bertillon, the founder of the first scientific method for identifyingcriminals—anthropometry, commonly known as Bertillonage. Like Locard,Bertillon was a forensic renaissance man who dabbled in numerous forensicarenas and believed fervently in the application of science to criminal inves-tigation. Bertillon went to crime scenes and, as Bertillon’s student, Locardwould have benefitted from his mentor’s belief in the application of scienceto the investigation of crime.

Divisible MatterInherent in Locard’s belief was that transfers required energy. Locardbelieved that it was the nature of a violent crime to provide the force nec-essary to effect an evidence transfer. Thus, a fiber from a sexual assault vic-tim’s blouse would undergo a force such that when an assailant’s shirtrubbed against it, the fiber would come loose and transfer to the assailant’sshirt. Similarly, fibers from the assailant’s shirt would transfer to the vic-tim’s blouse. However, the theory does not always explain reality. Certainfabrics “give up” their fibers easier than others and will require more ener-gy to release fibers. If sufficient energy isn’t there, a transfer might notoccur. Still, Locard’s ideas represent the reality of what forensic scientistsobserve in the laboratory today.

Inman and Rudin accepted Locard’s idea that it takes energy (force) to effectevidence transfer, making it what they refer to as one of two guiding princi-ples concerning the generation of evidence: fracture or divisible matter andtransfer or Locard’s exchange principle.5 For them, divisible matter implies a

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source of energy. They argue that something happens to evidence (theirpremise is that it is not evidence until this happens) which gives it the abili-ty to transfer. They call this a “fracture,” which requires energy. Once trans-ferred, however, they define this transferred material as evidence, whetherdiscovered or not:6

If the crime is never discovered or the evidence is never detected, mat-ter has still divided and transferred, and traits have still transferred.

They argue that the transfer occurs with only certain kinds of evidence,excluding impression and physical match evidence. They write thatLocard’s transfer principle might not explain these types of evidence.7

Recognize that divisible matter does not account for a large categoryof evidence, that of pattern transfer evidence, such as prints andimpressions. The transfer of matter requires its prior division; thetransfer of “traits” may not.

Defining a new fundamental principle while excluding a large category ofevidence types, a priori, seems problematic. If divisible matter really is anew fundamental principle of forensic science, one would expect it to applyto all evidence, regardless of type. Logically, then, Inman and Rudin’s con-cept would require a separate fundamental principle for each subcategory ofevidence. When Inman and Rudin discuss impression evidence, they statethe following:8

Although small amounts of physical matter may be transferred, it isthe pattern of transfer that concerns us, not the substance. Thereforedivisible matter does not apply.

Pattern evidence is created because a division from the original takesplace, which requires energy, albeit slight, and it occurs regardless ofwhether the transferred pattern has individualizing characteristics. In fact,Locard would likely disagree that the “substance” transferred has little orno value. As Locard wrote when he described a case in which the pattern(trait) itself had little individualizing value,9

The silverware of a restaurant had disappeared. Whoever had taken itmust have mounted a chair in order to reach the shelf where it waskept. As chance would have it, there was on the seat of the chair aforgotten napkin. A shapeless mark had been left on the napkin, notdistinct enough to indicate the kind of shoe worn by the individual.There was, however, a trace of mud on it, and this was examinedunder the microscope. In the midst of various animal and vegetablewaste matter, there were discovered a superabundance of fine granu-lations which were recognized as fecal material. This fact was areminder that during the same night scavengers had been working ina neighboring alley. Consequently, the investigation was directed tothese men.

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Fingerprints are another category of pattern evidence for which theremight not be sufficient individualizing characteristics to make specific iden-tifications. However, that does not imply that the only value of a latentprint is to make identifications. Fingerprints come from people, and while itmight not take much energy to divide the fingerprint residue from a fingerto a physical substrate, there is certainly a division process that takes placeof not just the pattern but also the constituents of the print itself. Theseconstituents have investigative value. For example, recent work by Leggettet al., which they term “lifestyle fingermarking,” suggests that drugs anddrug metabolites can be identified from fingerprints.10 In addition, if duringthe commission of a crime, a perpetrator strangles the victim and then sub-sequently touches a surface, the epithelial cells and hence DNA of the vic-tim would be in the perpetrator’s fingerprint residue.

The division of matter is shown schematically in Figure 6.1. The originalsource of the evidence comes from the participants in the crime—thescene, the victim, and the perpetrator—and the divided evidence goes intwo directions, each exposed to varying and likely different influences.

From the concept of divisible matter, Inman and Rudin describe threecorollaries, which they believe follow logically:11

Corollary 1: Some characteristics retained by the smaller pieces areunique to the original item or to the division process. These traits areuseful for individualizing all pieces to the original item.

Corollary 2: Some characteristics retained by the smaller pieces arecommon to the original item as well as to other items of similar man-ufacture. We rely on these traits to classify the item.

Corollary 3: Some characteristics of the original item will be lost orchanged during or after the moment of division and subsequent dis-persal; this confounds the attempt to infer a common source.

Evidence Dynamics

Corollary 3 considers that once division (fracture) has taken place, theuncertainty of a new environment intercedes. This concept was firstespoused by Chisum and Turvey (emphasis added) in their concept of evidence dynamics:12

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Figure 6.1: Divisible Matter

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The process of crime reconstruction is often built on the assump-tion that evidence left behind at a crime scene . . . is pristine. Thisassumption involves the belief that the process of taping off an area,limiting access, and setting about the task of taking pictures andmaking measurements ensures the integrity of the evidence foundwithin. Subsequently, any conclusions reached through forensicexaminations and reconstructions of that evidence are assumed tobe a reliable lens through which to view the crime. This assump-tion is not always accurate.

Evidence dynamics refers to an influence that “changes, relocates, obscures,or obliterates physical evidence, regardless of the intent.” Generally, thedynamic process begins at the instant that forces create a transfer of evi-dence and ends when the evidence reaches the courtroom. Actually, theprocess does not necessarily end there, as evidence used or not used in alegal proceeding might be required for subsequent hearings or trials.

The divided evidence, as in the principle of divisible matter, goes in one oftwo directions, one with the participants of the event and the other with itsoriginal source. Each becomes subjected to a new environment with thepotential for obliteration and contamination. Figure 6.2 lists influencesChisum and Turvey considered important.

Figure 6.2: Influences on Evidence Dynamics

• Offender actions• Victim actions• Secondary transfer• Witnesses

• Weather• Fire• Suppression efforts• Police

• EMTs• Scene investigators• Forensic scientists/forensic entomologists/criminalists

• Medical examiners/coroners

• Family activities

Cognizance of these influences should be prime investigative considera-tions. On-scene activity should consider whether any influence might haveaffected the evidence. If so, then appropriate action should be designedcarefully and implemented.


Questions1. What is meant by the Locard exchange principle?

2. How do the Locard exchange principle and the principle of divisible matter differ?

3. What is evidence dynamics?


Other Books of InterestInman, Keith, and Norah Rudin. Chapter 4: “The Origin of Evidence—Divisible Matter and Transfer.” The Principle and Practice ofCriminalistics. Boca Raton, FL: CRC Press, 2000.

Lecture 6 Notes1. Bisbing, Richard E. Fractured Patterns: Microscopical Investigation of Real Physical

Evidence. — http://www.modernmicroscopy.com/main.asp?article=11, 2004

2. Locard, Edmond. “The Analysis of Dust Traces.” American Journal of Police Science,1(3), 1930.

3. Gross, Hans. Handbuch für Untersuchungsrichter als System der Kriminalistik (Handbookfor Examining Magistrates as a System of Criminology). 2 vols., 1893.

4. Locard, Edmond. “The Analysis of Dust Traces.” Conclusion. American Journal of PoliceScience, 1(5), 1930, p. 509.

5. Inman, Keith, and Norah Rudin. Principles and Practice of Criminalistics: The Professionof Forensic Science. Pp. 75–99. Boca Raton, FL: CRC Press, 2000.

6. Ibid, p. 87.

7. Ibid, p. 78.

8. Ibid, p. 77.

9. Locard, Edmond. “The Analysis of Dust Traces.” Conclusion. American Journal of PoliceScience, 1(5), 1930, 496–514.

10. Leggett, Richard, Emma E. Lee-Smith, Sue M. Jickells, and David A. Russell. “‘Intelligent’Fingermarking: Simultaneous Identification of Drug Metabolites and Individuals by UsingAntibody-Functionalized Nanoparticles.” Angewandte Chemie International Edition. Vol.46, pp. 4100–4103, 2007.

11. Inman, Keith, and Norah Rudin. Principles and Practice of Criminalistics: The Professionof Forensic Science. P. 87.

12. Chisum, W. Jerry, and Brent E. Turvey. “Evidence Dynamics: Locard’s Exchange Principleand Crime Reconstruction.” Journal of Behavioral Profiling. Vol. 1(1), 2000.

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The general concept employed for finding probative evidence goes some-thing like, “evidence leads to evidence.” Many crime scene texts ignorethis topic and focus instead on the various classes of evidence without con-sidering the necessary preamble that places evidence into its proper per-spective. Investigators need to realize that this concept is really a discussionof scenes within a scene. Macroscenes and microscenes form the basis of aholistic1 approach to the investigation.

The Macroscene

The macroscene is what an investigator sees on entering the scene. It iswhat assaults the visual, olfactory, and psychological senses and is the inves-tigator’s first visual impression.

My first scene was a homicide in a dark alley outside of a bar in Pittsburgh.While the scene is not a recurring memory, it easily surfaces. A youngwoman, lying face up, had been rendered unrecognizable by a large rock,her face bashed in and her head turned into a fleshy pulp. Hundreds ofscenes later that scene still lives, while others, many more violent, arepushed further from the conscious mind. The reason for mentioning this isthat our senses are easily overwhelmed, and it is easy to lose focus.

The scene diagram in Figure 7.1 is a hypothetical shooting incident.Consider the macroscene elements: a body, a bullet hole in a window,blood on the entrance doorknob on the exterior surface, blood trail on thefloor, and a small spray of blood spatter on the floor to the right of wherethe blood trail begins. A gunshot wound to the deceased, not part of theimmediate macroscene, is hidden because of the deceased’s position on thefloor, although a pool of blood has formed under him.

The macroscene includes obviously visible aspects, while other subtle ele-ments can be made visual by employing simple techniques. For example,the window has sub-macroscene elements, the bullet hole being the mostobvious. Others include features (elements) that do not immediately stand

Lecture 7

Macroscenes and Microscenes andFinding Associated Evidence

The Suggested Reading for this lecture is Robert C. Shaler’s Crime Scene Forensics: A Scientific Method Approach, chapters 17–19.

Visible and invisible evidentiary elements at the scene are defined asmacroscenes and microscenes, respectively. The evidence associatedwith each is termed elements.

out: fingerprints on the windowsill, shoeprints in dust on the pavementunderneath the window, and forehead and/or fingerprints on the glass frompressing against the window. These evidentiary elements represent the win-dow’s sub-scene, and they, too, must be defined as macroscene elementsbecause they can be easily visualized using common scene investigativetools—alternate light source (ALS), flashlight, or dusting powder.

The deceased is another part of the macroscene. The body evokes a visceralresponse and tends to become a focal point of the investigation. Noviceinvestigators quickly equate the body with the scene and ignore the othermacroscene elements, but a dead body should never overshadow other ele-ments of the macroscene. Like the window, the body has its own set ofmacroscene elements: bloodstains and bloodstain patterns on hands andclothing, gunshot residue, contusions, sharp force wounds, and other marksthat will be interpreted and archived by the medical examiner.

The macroscene also includes evidence that is invisible to the naked eyebut can be made visible at the scene. Thus, a fingerprint on a door jamb isinvisible until dusted. On the other hand, a fingerprint that is not visualizedat the scene is latent evidence and thus becomes part of the microscene.Macroscene elements typically consume much of the energy, thought, andtime of scene investigators. For the purposes of this discussion, we definethe macroscene as follows:

The individual, visible, or visualized elements of the crime scene,each of which is a part of the whole.

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Figure 7.1: Hypothetical Homicide Scene

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The Microscene: Trace Evidence or Locard Elements

Evidence that is not visible and which cannot be made visible at thescene is the microscopic or microscene. Nevertheless, the microscene elements hold no less importance for the investigation, and they must becollected and preserved.

The line between macroscene elements and microscene elements is obvi-ously blurred and not clearly defined. For example, a blond hair on a blackT-shirt might correctly be considered a macroscene element. However, ablack hair on a black T-shirt might correctly be thought of as a microsceneelement. Such restrictive definitions are not as important as the conceptand how it is thought of at the scene.

The difficulty in locating and collecting these microscene elements lies inthe fact that they are invisible; finding them requires the application of thescientific method through diligence and using a systematic and logicalapproach. The logic requires a consideration of which macroscene elementsare present, given the scene, the crime type, and the type of trace evi-dence—microscene elements—expected to be associated with them.

There is an intimate relationship between macro- and microscenes becausethe creation of one, by definition, creates the other; the microscene ele-ments are the consequence of activity that created macroscene elements.For example, a struggle between two people might result in one of the twoending up dead. The body becomes only one element of the macroscene,but it also has a macroscene: bloodstains, knife wounds, contusions, andothers. It also has a microscene (for example: hairs, fibers, fingerprints, andgunshot residue). Figure 7.2 illustrates the obvious interrelationshipbetween the macroscene and the microscene.

Figure 7.2: Relatedness of Macro- and Microscene Elements

We define the microscene as follows:

Invisible, microscopic or latent traces intimately associated with themacroscene and commonly called trace evidence but could be definedas Locard elements.

It seems obvious that when two participants interact physical materialtransfers from one to the other and to the location where the activitytakes place, the scene. But to what extent does this really happen? Cansuch transfers occur a second or more times? What evidence (debris) isnormally present in the area of, say, a struggle? The first question harkensback to the discussion of the energy it takes to make a fracture (divisiblematter) happen.

Chesterene Cwiklik2 considered the second question, a phenomenoncalled “secondary transfer,” how often it occurs, and the effect of suchtransfers on an investigation (emphasis added):

. . . particles and fibers abraded, flaked, broken, or torn from theitems themselves as well as other particles and fibers that have col-lected on the surface of each item prior to their contact. The latterparticles and fibers are non-component debris: not an intrinsic (com-ponent) part of the items themselves. Their transfer is referred to assecondary, tertiary, and higher degrees of transfer: indirect transferfrom the source item.

Cwiklik also considered the third question and defined sets of microsceneelements intrinsic and exogenous to macroscenes. She placed them intospecific categories, defining each (see Figure 7.3).

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Figure 7.3: Hypothetical Microscene Elements

The microscene elements (evidence) of a particular macroscene environ-ment are divided into families, each of which comprises a set of debris (par-ticles and fibers) and an associated subset of debris (particles and fibers).There are also stray particles and fibers and small subsets that hold little

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investigative value. Each set shares a common life and represents a recordof the daily life of that specific macroscene environment.

The subsets within each set arise from a diverse set of origins, includinghairs and skin flakes from the occupants and fibers indigenous to that spe-cific environment—for example, carpet fibers, clothing fibers from awardrobe, processes that occurred elsewhere (debris shed from clothing orfootwear), and aerial transport (soil, traffic dust, insect parts, botanicalssuch as pollen and/or spores).

Different from these is a subset of debris that occurs from occasionalevents. These define a timeline for activity taking place within the part ofthe macroscene that defines the crime scene. Thus, examining a singlemacroscene environment at a crime scene reflects the daily record of thatenvironment and a timeline of transient events that took place inside thatenvironment. Investigators should be cognizant that each microscene hasthis information and then tailor the search and recovery of the evidence sothat the daily record and the occasional record are not lost.

The Transfer of Microscene Elements

Consider how much “stuff” there is in the world that could be transferredin an environment that is not usually associated with a crime. The amountof transferrable material is probably limitless, and each of us is exposed to asignificant amount of transferrable material every day. So what is the impli-cation of environments having a limitless supply of transferrable material?

Suppose you shake hands with someone who then visits a mutual friend.They argue and the mutual friend is murdered. What is the probabilitythat your skin cells (DNA) are on the murder weapon, a knife taken fromthe mutual friend’s kitchen? If fingerprints on the knife are smudged,they are useless for comparison purposes. But your DNA would be at themurder scene.

Primary Transfer

There are instances when transfer does not easily, or ever, take place.Consider footwear impressions. Some fall into the macroscene element cat-egory because they are either immediately visible (for example, wet originimpressions) or they are latent and can be made visible (for example, dryorigin impressions highlighted using oblique lighting). For the impressionpattern to be transferred, the shoe and the receiving surface characteristicsmust be able to produce or accept an impression transfer, but not all sur-faces equally accept impression evidence.3

A wet shoe will likely leave a print on most surfaces, except a carpet. Adry shoe with dust on the sole will not likely leave a print on a floor thatis already dirty, and a clean dry shoe will not likely leave detectable printson a dirty floor, a carpet, or a clean unwaxed floor. So while Locard’sexchange principle theoretically guarantees a transfer of evidence, there

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are practical considerations that investigators must consider logically whilesearching for evidence.

For fibers, Pounds and Smalldon4 and Robertson and Roux5 showed thatthe number of fibers transferred depended on a number of factors, includ-ing surface area, number of contacts, the force/pressure applied during con-tact, and the type, age, wear, morphology, and thickness of the fibers.

Crime scene scientists/investigators should understand and examine, atthe scene if possible, the composition of fabrics situated in areas wheretransfers might take place. The clothing of the deceased should be evaluat-ed to ascertain the potential for the primary fiber transfer from the crimescene and/or the victim to a perpetrator during a violent event. The crimelaboratory criminalist will search the garment, find the transferred fibers,and compare them to exemplars.

An important category of evidence is glass. When it breaks, it spews frag-ments, or shards, in a 360-degree variable pattern. Essentially, glass frag-ments fly backward and forward after the break, which means glass shardsmight be found on a burglar’s clothing. Shards will be found up to a dis-tance of at least ten feet, with most shards within approximately a three-to-five-foot area. Also, the highest distribution of fragments would be expectedin the area between the 45-degree lines on either side of the impact point.4

The higher the impact force, the smaller the fragments. These small shardshave extremely sharp edges, which theoretically can become imbedded inthe soles of shoes or the weave of fabrics.

© Shutterstock.com

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The investigation team should determine the radius of the distribution pat-tern and locate where the highest density is located. Within the glass distri-bution pattern, there might be a void, which should alert the scene scien-tist/investigator that shards had impacted the clothing of the burglar andwhere the person was standing when breaking the glass. Samples of glassshould be collected for an appropriate scientific comparison.

Secondary Transfer

Secondary transfer occurs when trace evidence, such as fibers from a pri-mary target, transfer to a secondary target. That is, a primary transfer hasalready taken place from one fabric to another—garment 1 to garment 2. If the receiving garment (garment 2) subsequently contacts another receiv-ing garment (garment 3), fibers can transfer from garment 2 to garment 3,resulting in a small percent of the fibers transferred from garment 1 ontogarment 3.

The scene scientist/investigator should not lose sight of the fact that sec-ondary transfers are possible. Modern society is entirely insulated. So it ispossible to envision that fibers transfer from one garment to another ran-domly as we move from place to place. Isn’t this the Locard exchange prin-ciple in action? We are a living history of our daily environment. If some-one attacks us in our home and physical contact occurs, there is a reason-able chance that a transfer of fibers and other trace evidence will takeplace. Some of these transfers might involve secondary or higher transfers.

The Persistence of Locard Elements

Studies have been done that show how persistent fibers are after transfer(that is, the length of time transferred fibers remain on a particular surfaceafter an event) and that persistence is the concern of the laboratory crimi-nalist with respect to interpreting the meaning of the trace evidence found.

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Questions1. What is the macroscene?

2. What is the microscene?


Other Books of InterestInman, Keith, and Norah Rudin. Chapter 4: “The Origin of Evidence—Divisible Matter and Transfer.” The Principle and Practice ofCriminalistics. Boca Raton, FL: CRC Press, 2000.

Lecture 7 Notes1. Holistic is a term used throughout this course. It is defined by the Merriam-Webster Online

Dictionary: “2. relating to or concerned with wholes or with complete systems rather thanwith the analysis of, treatment of, or dissection into parts <holistic medicine attempts totreat both the mind and the body> <holistic ecology views humans and the environment asa single system> — http://www.merriam-webster.com/dictionary/holistic

2. Cwiklik, Chesterene. “An Evaluation of the Significance of Transfers of Debris: Criteria forAssociation and Exclusion.” Journal of Forensic Science. 44(6), 1999, pp. 1136–1150.

3. Bodziak, William J. Footwear Impression Evidence: Detection, Recovery, and Examination.Pp. 17–20. Boca Raton, FL: CRC Press, 2000.

4. Pounds, C.A., and K.W. Smalldon. “The Distribution of Glass Fragments in Front of aBroken Window and Transfer of Fragments to Individuals Standing Nearby.” Journal ofForensic Science, 18 (1978) 197–203.

5. Robertson, James, and Claude Roux. Chapter 5.1: “From the Crime Scene to theLaboratory.” Forensic Examination of Fibres. 2nd ed. Eds. James Robertson and MichaelGrieve. Boca Raton, FL: CRC Press, 1999, p. 89.

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Certain crime types spawn specific types of evidence. Finding the evidencethat links the participants to the scene is why crime scene investigationsexist and why searching is critical. From a philosophical perspective we canlogically split the crime scene search into two parts (see Figure 8.1).

1. The mental approach, the logic required to devise a strategy for thesearch as well as the processes that will be used.

2. The by-product of two activities: the original walkthroughand archiving.

The walkthrough is when the team leader first sees the macroscene ele-ments and begins to consider them in the context of the overall sceneinvestigation, mentally gathering information about the scope, size, andlocation of obvious evidence and the not-so-obvious fragile evidence.

Archiving is included because it, too, presents a pictorial perspective ofhow the macroscene relates to the relative location of evidence. Reviewingdigital photographs from the archiving process in the last phase of theinvestigation can also help pinpoint the relatedness of evidence that hadbeen missed. If the archivists and the team leader are in synch, this infor-mation will slowly emerge from the chaos that defines crime scenes.

Using this collaborative information, the team leader can devise a searchstrategy based solely on logic and not a “method” published in a textbook.The mental and physical activities required to conduct a proper search areinextricably joined, such that, if crime scene management is the glue thatholds the investigation together, the scene search is the meat and potatoes.

Processing Versus Investigation

Modern books on crime scene investigation lull even seasoned investigatorsinto believing that searching the scene is a simple, thoughtless process thatanyone can perform. Police agencies often call it “processing the scene,” butscene “processing” is more than a “process.” It is a scientific endeavor, a sci-entific investigation, and it is certainly far from simple.

Lecture 8

Searching: The Meat and Potatoes of the Investigation

The Suggested Reading for this lecture is Robert C. Shaler’s Crime Scene Forensics: A Scientific Method Approach, chapter 5: “Searching:Logic in Action.”

A reasoned approach to finding evidence is needed to properly searchthe crime scene. The intellectual approach to the search—searching withpurpose—is presented as the meat and potatoes of the investigation.

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In truth, searching the scene is the crux of the investigation. Certainlyarchiving is important, for if done badly, anyone examining the scene afterthe fact will not “see” the original scene. A poor approach to searchingleads to second guessing, which happens if the search is not conducted logi-cally and systematically. The crime scene investigation must be treated likeany scientific investigation/research project, the difference being that itinvolves law enforcement’s investigative arm. Thus the scene investigationis not a blind process but one of immense complexity.

Defining the SearchThe team leader should be considering specific search parameters toensure the team does not miss important or critically probative evidence.This logical approach contrasts with modern crime scene investigationtexts, which consider the scene search as a methodical process presentedas a “method.” That is, they promulgate specific search or “named” proce-dures designed for specific crime scene types. Such a simplistic approach isas ridiculous as the term “processing” because it conveys the impressionthat scene searches are mindlessly simple.

To be fair, the intent of these “methods” is to present investigators a road -map for avoiding serious mistakes. As Gardner points out,1 “The specificmethod the crime scene team chooses is really unimportant so long as themethod employed is methodical and systematic.” Gardner fails to recognize,however, that the search should also be logical.

Figure 8.1: A Scene Search Philosophy

The Crime Scene

The place where individuals participated in an event at a point in time thatresulted in the creation of evidence.

Finding evidence linking these participants to the scene is why crime sceneinvestigations exist and why searching is critical.

Scene Type Examples

1. Hit and Run Casesa. Two cars—one hitting the other—one leaves the scene.b. A single car hitting a pedestrian and leaving the scene.

2. Sexual Battery Casea. Assailant breaks into apartment or house.b. Assailant abducts the victim off the street.

3. Homicide Casesa. Violent dispute between spouses.b. A shooting in a drug case.

Searches Split into Two Parts

1. The logic required to devise a strategy for the search and theprocesses employed.

2. The by-product of two activities: The original walkthrough and archiving.

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Figure 8.2: Relationship Among Management, Archiving, and Searching

Critically Interrelated Scene Investigative Components

Nature of the Scene

Each scene presents investigators with a different “look.” Homicides inlarge cities often occur in apartments. While many may have the same setof circumstances, the truth is that they are not the same. Each is differentand each has a different geography and different clutter. Some might haveair conditioning in the summer while others may be stiflingly hot. The dif-ference temperature and humidity make can dramatically affect the successand efficiency of the investigation. As an example, when the temperature is97˚F and the humidity 92 percent, odors from a decomposing body will beoppressive. If the scene has air conditioning, these same odors will be man-ageable. In hot scenes, excessive perspiring makes investigators work unin-tentionally faster, which can result in a flawed investigation.

Outdoor scenes have a Pandora’s box of environmental obstacles. A scenein the woods differs from a shooting in a parking lot. A scene in the moun-tains in the middle of winter after a snow storm has obstacles different thanthe same scene in the spring. Each scene has obstacles and requires a strat-egy born from logic to search it correctly and efficiently.

Logic

All scene searches must embrace a logical approach. This means reasoningproperly to recognize relevant evidence.2 Finding relevant evidence requires

Table 8.1: First Scene Considerations

Scene Considerations Other Issues

Size—Physical Terms Obstacles

Relevance—Obvious Evidence Additional Resources Required

Fragile Evidence Media

Scope—Crime Type Command Center/ContainmentPrimary/Secondary/Staged

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Table 8.2: Attributes of a Successful Scene Search

Attributes of a Successful Search Other Issues

Effective Management Experience, Knowledge, Leadership

Understanding the Nature of the Scene Size, Scope, Weather, Obstacles,On-Scene Environment, Lighting, etc.

Appropriate Logic Employing the Scientific Method

Systematic Approach Not Random

Creative Thinking Relative Associations of Scene Elements

a systematic approach. As Gardner points out, searches must be methodicaland systematic. He defines methodical as “marked by ordered and systematichabits or behavior,” which he considers the “application of established pro-cedures and practices.” In the context of this discussion, however, this is notnecessarily true. The fact is, ideally, the crime (not just the crime type)defines the evidence that is present. This does not mean that all homicideshave the same evidence; however, two homicides in which each deceased isthe victim of blunt force trauma may have similar types of evidence present,but there will also be differences.

The approach to the scene search should be guided by the question of rele-vance for that specific scene. As Inman and Rudin put it, searching is look-ing with purpose,2 which means locating probative evidence relevant to thespecific crime in a particular place and circumstance.

Expectations during the scene investigation can translate to the search.Knowing who is arrested can present a problem because it is human natureto unintentionally search for specific suspect-related evidence. The scientificmethod eschews that approach.

Accepting or rejecting evidence should be based on the totality of evidenceat the scene. Thus looking for long blond hairs on the deceased’s clothingbecause the boyfriend has long blond hair is not a reasoned approach.

© Shutterstock.com

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However, looking for hairs, in general, on the deceased’s clothing is reason-able, and if they turn out to be long black hairs, so be it.

Systematic

Gardner suggests that a crime scene search should be methodical and sys-tematic, and defines systematic as “purposefully regular,”3 which impliesthe application of a search “method.” For military and paramilitary agen-cies this is easy to implement because it gives their investigators a way tostandardize the search to accomplish a specific goal. Accountability is easi-er to ascertain and standardization gives the appearance of thoroughness.In fact, the opposite may be the case. A method search is exactly that: away to do something that is rote, repeatable, and efficient. However,unless logic is employed, evidence will be missed and evidence that is notrelevant will be collected.

Creative Thinking: Out of the Box

The most successful scene detectives and criminalists have an innateability to think creatively. It’s a skill that some learn over time throughexperience. However, some “see” connections where others, even experi-enced investigators, do not. Those possessing this ability are the bestcrime scene investigators.


Questions1. What two aspects of the crime scene investigation are intimately linked

to the search?

2. What is the difference between scene processing and scene investigation?

3. List five attributes of a successful scene search.


Other Books of InterestFisher, Barry A.J. Techniques of Crime Scene Investigation. 7th ed. BocaRaton, FL: CRC Press, 2004.

Lee, Henry C., Timothy Palmbach, and Marilyn T. Miller. Henry Lee’sCrime Scene Handbook. Burlington, MA: Elsevier Academic Press, 2005.

Shaler, Robert C. Who They Were: Inside the World Trade Center DNAStory: The Unprecedented Effort to Identify the Missing. New York: FreePress, 2005.

Lecture 8 Notes1. Gardner, Ross M. Chapter 5: “Understanding Crime Scene Protocols and Their Effect on

Reconstruction,” page 101. The Practical Aspects of Crime Scene Investigation andReconstruction. Boca Raton, FL: CRC Press, 2009.

2. Inman, Keith, and Norah Rudin. Chapter 5: “The Recognition of Physical Evidence,” p. 101.Principles and Practice of Criminalistics: The Profession of Forensic Science. Boca Raton,FL: CRC Press, 2000.

3. Gardner, Ross M. Chapter 5: “Understanding Crime Scene Protocols and Their Effect onReconstruction,” page 101. The Practical Aspects of Crime Scene Investigation andReconstruction. Boca Raton, FL: CRC Press, 2009.

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Although method searches are not always appropriate, there is a certaintruth in them because crime scenes have been successfully searched usingmethods for a long time. And passing on these methods is an attempt toteach how to be proficient crime scene searchers.

Outdoor and indoor searches have unique challenges. Each scene presents aspecific set of obstacles and challenges, and each can be adequately searchedusing an appropriate method. In an indoor search, the layout of the premisesand the constraints of furniture and tight spaces present challenges notencountered in outdoor scenes. Vehicle scenes present challenges of anotherkind: two scenes in one: the inside and outside of the vehicle.

Logic is the mechanism for finding objective evidence so the jury or Trier ofFact can evaluate the evidence to ascertain—as closely as possible—theground truth of a case. Searching is when investigators display their powersof observation, tendencies for bias, attention to detail, and experience.

Historically, crime scene texts and scene instructors devote space (andtime) to “method” searching that represents search experience by investi-gators who share their experiences because of their personal successes.The following is a discussion of these “methods” with the understandingthat applying them without logic is a recipe for failure.

Grid or Line Search Methods

One variation of the line method is the grid search. Like all “method”searches, it, too, is a roadmap, and if investigators follow it correctly andstick to it, the search will likely be conducted properly. The grid search is amore powerful variant of simpler search types, such as the line and parallelmethods. The reason is that the grid search is in reality a perpendicularsearch, because it happens in two directions.

In classes, students are presented with an outdoor area to search as anexercise to illustrate how to conduct a grid search. The search is usually inthe woods or in a field.

Lecture 9

Scene Search Methods

The Suggested Reading for this lecture is Robert C. Shaler’s Crime Scene Forensics: A Scientific Method Approach, chapter 5: “Searching:Logic in Action.”

Named method searches designed to minimize mistakes and missedevidence are typically taught to inexperienced investigators. If these arelogical and systematic, they have value as search methods. Pressure atthe scene affects the investigative process.

The line of searchers moves in one direction until they have searched theentire area. Next, they search perpendicularly to the first pass. Typically,they miss evidence on the first pass but almost invariably find it on the per-pendicular. Invariably, they are surprised that they missed evidence on thefirst pass because they felt that they were doing a thorough job. The exer-cise cements in their minds the need to conduct a thorough search.

The difficulty is to keep the team moving in a straight line. Some studentstend to move faster or slower. Communication, at first, is also a problem,because when a student finds evidence, one end of the line stops but theother end keeps moving. On the second pass, they usually get it right.

A variation of the grid search, the line search or single-pass search, isnever appropriate because it is inherently constructed to miss evidence. Forlarge outdoor scenes, such as an airplane crash, it may be appropriate togrid the scene and then conduct individual grid searches within each majorgrid. An example was the World Trade Center scene after the 2001 attacks.The scene was gridded into seventy-foot squares and each grid searchedsystematically. That scene was different than most because each grid had3D characteristics, surface and depth.*

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Figure 9.1: Schematic Illustration of the Grid Search

Figure 9.2: Schematic of Line or Strip Search

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Indoor Scenes: Zone and Point-to-Point Searches

Zone Searches

Zone and point-to-point searches are fundamentally different approachesfor searching indoor scenes. The zone method illustrated in Figure 9.4 isfor prioritizing search areas at an indoor scene. Areas having the most obvi-ous activity become the primary search areas. Zones where the body wasfound and the entrance and exit paths, respectively, would be the primesearch areas. Other zones might not appear as important, but no part of thescene should be ignored.

Point-to-Point Search

The point-to-point search is similar to the zone method because it cordonsthe scene into specific search areas. The difference lies in the reason formaking the splits, which depends on the location of evidence instead ofdividing an area, such as a house, into zones. Found evidence dictates theareas to search. Logic also plays a part in targeting areas where evidencemight be: entrance or egress points, impression evidence, or weapons. Thus,this search type employs a form of logic. The problem is that a competentcrime scene search is not simple, and it would be a mistake to employ amethod simply because someone wrote about it in a book.

A systematic search is characterized by thoroughness and regularity.Any systematic search is appropriate as long as it is done correctly.Success is determined by how well the lead investigator/team leadermanages the team.

At most scenes, quality procedures, as in quality assurance, are mostlynonexistent. Another barometer of crime scene search competence is oftenthat a suspect has been convicted. This is fallacious reasoning, because thecourt system is not an effective arbiter of quality or competence. No oneknows whether exculpatory evidence had been missed.

Other outdoor line search methods are diagrammed as follows. Under mostcircumstances, these lead to missed evidence, especially in complicatedareas where evidence might be difficult to see (for example, woods orfields). On surfaces such as concrete and paved parking lots, where theline-of-sight is unhindered, these methods are appropriate.

Figure 9.3: Schematic of Parallel Search

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Figure 9.4: Schematic of the Zone Method

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Clockwise/Counterclockwise Search

Another approach, the clockwise search, requires investigators to search,sequentially, clockwise while looking from the waist to the floor and thencounterclockwise while searching from the waist to the ceiling. Envisioninga specific circumstance when this might be employed is, to be kind, elusive.There is, certainly, the question of how this method came about. Perhaps itstemmed from someone missing evidence on the ceiling. Vowing never tolet that happen again, a frustrated team leader contrived this method so thathis team would always search high and low for probative evidence. Seeingthis method in action would appear laughable, as two scene investigatorswalk sequentially clockwise and then counterclockwise, training their eyeson only the waist-high and then on waist-low areas of the scene, respective-ly. Logical and systematic searches render this approach unnecessary.

Figure 9.5: Characteristics of the Link Method: Thinking the Search

The Link Method

Unlike the methods described above, the link method is not a roadmap perse, but instead it relies on logic to lead the investigator to critical evidence.The investigator works to understand and exploit evidentiary associations atthe scene. This is based on findings or observations and then applying logicas the tool to proceed. In a sexual assault scene, certain evidence types arecommon (for example, blood, semen, and bite marks), but other evidencemight also be present, such as footwear impression, discarded weapons, orski masks. The position of the body, the location of a knife, and other spe-cific evidence types dictate how and perhaps if to proceed.

Ray or Wheel SearchAnother widely illustrated method is thewheel or ray (Figure 9.6). Any thinking per-son would take one look at this diagram andwonder who had the original idea. Whywould anyone seriously consider using thisapproach for any scene except for one withan incredibly small footprint?

Employing On-Scene Technologyand StatementsLogic in action means taking advantage ofeverything available to narrow the search area. An example might be a bur-glar caught on a surveillance camera that captured the individual’s paththrough the scene and the areas he touched. This dramatically narrows thesearch area because the investigator knows exactly how the burglar got insidethe premises and what he touched. Most of the logic of determining where tosearch is gone. Areas not captured by the video, however, cannot be dis-missed easily and must be searched. Statements by witnesses and victims canalso help narrow the search area.

Pressures at the SceneIdeally, pressures of the search would relate only to finding probative evi-dence and archiving the scene properly. However, the reality is that pres-sures exist on a multitude of levels. Certainly, there is an internal pressureto locate evidence, but pressure can come from outside.

• The media hounding the team leader for information.

• The team leader being tied up with detectives.

• The size of the team: members of a small team may work welltogether but will have more work, and rushing can create errors.

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Figure 9.6:Ray or Wheel Search

© Thinkstock.com

• Demanding superiors creating pressure to speed the search and pro-vide investigative information quickly.

• Environmental insults creating pressures on outdoor scenes.

• Political pressure getting raised in high-profile cases (police shoot-ings, deaths of well-known individuals, cases of bias, etc.).

Constraints

All scenes have constraints, whether these have to do with time, work-load, the weather, or geography.

Archiving and Searching Common Scene Types

Investigators encounter certain crime scene types routinely. Burglarieshave evidence commonly associated with them and so do homicides andsexual assaults. Still, each crime scene is unique and each presents chal-lenges different from the so-called norm for that crime type. With respect toevidence, different crime types present overlapping categories of evidencebecause, for example, what starts as a burglary may well end up as a homi-cide or a sexual assault.

Searching and archiving are overlapping exercises. The forensic archivist’sresponsibility is to capture the scene photographically or by sketching,which should ultimately lead to evidence that is collected. During thearchiving process, the investigator who “finds” evidence should alert thesearch team and team leader.

Figure 9.7 gives an overview of common evidence types associated withcertain crime types. Recognize that some of these commonly overlap.

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Figure 9.7: Selected Examples of Evidence in Case Types

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Technology to Aid Searching

Most search activities are visual, but using technology such as the alternatelight source (ALS) can improve the quality of the evidence located. Table9.1 provides the wavelengths used on an ALS for locating specific types of evidence.

Searching for Trace Evidence: Overview Considerations

The search for evidence does not end with visible elements. The searchteam must also consider invisible evidence. Collecting trace evidence iscritically important, and it requires employing a logical thought process ofknowing where to look and using standard techniques to collect it.

Table 9.2 is a limited checklist of places where microscene evidence mightlogically be found. It also explains the reasons why these are places tobegin searching.

The flip side of the search coin for trace evidence is knowing where not tosearch. It would be ridiculous for the scene scientist/investigator to vacu-um or tape lift all items of furniture at the scene to find the one piece offurniture that has fiber evidence from a perpetrator’s shirt. The subsequentlaboratory work is time consuming and tedious, and submitting hit-or-missevidence in bulk to cover a shoddy scene investigation will incur the wrathof the crime laboratory scientist. Obviously, finding and collecting probativeevidence is critical, but collecting evidence without a valid reason is stupid-ity in action.

Table 9.1: Using the ALS to Locate Evidence

Wavelength Viewing(nanometers [nm]) Principal Use Lens

White Light General scene scanning ClearFingerprints on shiny surfaces

UV–365 Hair, fiber, fluorescent material-powders Clear orBody fluids/bruises/bite marks YellowFood stains

415 Bloodstains ClearFood stains

450 Body fluids, semen, blood OrangePowders/teeth/bonesPaint/fibers/accelerants

465–485 Fluorescent materials/powders OrangeBody fluids

515–535 Diazafluoren (DFO)/Indanedione Reddeveloped fingerprintsSuper Glue fumed fingerprints

570 Inks Red

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Table 9.2: Locations Where Trace Evidence Might Be Found

Location Reason

Points of entrance and egress These are areas where the perpetratorsmight have been and can be locations offibers, hairs, and other evidence.

Areas of struggle These areas are prime targets for hairs,fibers, blood, and saliva. They includefurniture and carpets, and should notbe overlooked.

The clothing and shoes of participants The clothing of victims and suspects inin the crime (victims and suspects) direct contact with each other should

have fiber, hair, saliva, and bloodevidence present.

Furniture: understanding the transfer Fabric furniture involved in a strugglepotential of certain fabrics (turned over chairs, for example) has

the potential of attracting fibers andhairs. The likelihood depends on thecharacteristics of the fabric—whetherit accepts and/or gives up its fibersreadily. These can also have salivaand blood.

Bodies of decedents The body and its clothing.

Fingernails Anyone involved in a struggle has the possibility of having trace evidenceunder the fingernails: hairs, fibers,saliva, and blood.

Areas searched by the perpetrators If a perpetrator (for example, a burglar)is searching for valuables, the areashe searched are prime targets fortrace evidence.

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Questions1. Name four “named” method searches.

2. Assume you are searching a wooded area for skeletonized body parts.Which of the following would be your first choice?

a. The point-to-point search

b. The line search

c. The spiral search

d. None of the above

3. What wavelength is used on the ALS to locate semen evidence?

4. Which of the following is correct? All searches should be

a. Regular and logical

b. Thorough and systematic

c. Systematic and logical

d. Regular and thorough


Other Books of InterestLee, Henry C., Timothy Palmbach, and Marilyn T. Miller. Henry Lee’sCrime Scene Handbook. Burlington, MA: Elsevier Academic Press, 2005.

Lecture 9 Notes*Shaler, Robert C. Who They Were: Inside the World Trade Center DNA Story: TheUnprecedented Effort to Identify the Missing. New York: Free Press, 2005.

Archiving versus documentation is the process of creating a permanentrecord of the scene such that it is compatible with a modern digitalworld. The archiving processes include photography, video, sketchingand 3D imaging.

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© Shutterstock.com

Lecture 10

Introduction to Forensic Archiving: Forensic Photography

The Suggested Reading for this lecture is Robert C. Shaler’s Crime Scene Forensics: A Scientific Method Approach, chapter 6: “ThePrinciples of Forensic Photography.”

No single archiving method is sufficient, and the approaches vary from thesimple process of taking notes to using increasingly complex technology. Anagency using only 35 mm or digital cameras coupled with sketching andmeasuring is not doing its job properly. Similarly, videography alone is insuf-ficient and inadequate, as are the newer 3D archiving systems.

Active Archiving

Active archiving is the process of combining “rote,” passive archiving withan engaged brain. Taking establishing (overview) photographs of a roomwith a dead body while simply moving from perspective to perspective andsnapping photographs is passive archiving.

The archivist should be thinking about the visual scene elements. Is itenough to record the body lying on the floor in a pool of blood? No! It is

also critical that photographs include the tip of the knife sticking out fromunder the deceased and the knife just hidden under the sofa six feet away.Either perspective might be a critical part of the eventual scene recon-struction because subsequent photographs might miss that angle.

The archiving process is the visible investigation of the scene and is anessential aspect of an active investigation. The forensic photographershouldn’t care about being artistically creative, but being creative in theforensic sense. Photographs must capture the best perspectives at the sceneto capture its story. The forensic photographer uses the scene to guide thecontinuum of photographs from relevant evidence to relevant evidence.

The Purpose of Forensic Photography

Forensic photography has far-reaching implications, but the most obviouspurposes are straightforward.

• Record and preserve the as-found condition of the scene.

• Show the relative position of evidence at the scene.

• Establish the relative dimensions of evidence.

• Cross-complement other archiving techniques.

The overriding responsibility of the investigator is to capture the scenewithout missing the integral relationships of evidence. The paradox is thatforensic photography is an insufficient medium to capture everything.

Critical Aspects of Forensic Photography

For appropriate forensic photography, the properly outfitted photographerneeds the following photographic equipment at a minimum.

• A single-lens reflex (SLR) digital camera having, minimally, thecapability to take burst photos, adjustable white balance choices,and a menu for manipulating the white balance, ISO (image sensor)selections ranging from 100 to 6400, manual override modes (aper-ture, shutter, and manual and program priorities), and exposurecompensation. It should also have an external flash attachment.

• Close-up macro lens: f/1.4 or f/2.8, 60 mm.

• Zoom lenses: f/2.8, 18 to 70 mm, and 70 to 200 mm, or an f/3.5,18 to 200 mm.

• Polarizing lenses to eliminate glare.

• Ball-head tripod.

• External flash.

• Lighting slaves.

• Light towers.

• Appropriate filters for use with an ALS: yellow, orange, and red.

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• Ring flash attachment.

• Scales.

Essential Skills of Forensic Photography: Focus

If it’s not in focus, the rest doesn’t matter.

Gone are the days when the photographer has to wait for the film to bedeveloped before learning whether a photo is in “tack sharp” focus1. Mostcheck the LCD viewer on the back of the camera to inspect photographs.The LCD viewer can fool you, however. Although the photograph mightappear to be in focus, it might be out of focus when viewed on the comput-er screen. Having photographs in tack-sharp focus is vitally important toprofessional and forensic photographers.

• Use a tripod with a ball-head mount or at least a monopod (thereare situations, however, where hand-held is the only way to get thecorrect photograph).

• Pressing the shutter moves the camera. Use a cable release, theself-timer function, or the infrared wireless remote shutter.

• Lock the camera’s mirror in the up position. Normally, the cameramoves the mirror up and locks it while taking the photograph, andthis causes movement inside the camera. The solution is to movethe mirror up manually. According to Kelby,2 this is the secondmost important precaution next to a tripod to keeping photographstack sharp.

• Vibration Reduction (VR), or Image Stabilization (IS), is designed tominimize vibration that comes from pressing the shutter. The rulesof thumb: If you are hand-holding the camera, activate the VR sys-tem. If the camera is on a tripod, deactivate the VR system.

• Shoot at the lens’s sharpest aperture. Generally, this is about twofull stops smaller than wide open. Each lens will have a sweet spotfrom which it will deliver its sharpest images.

• Use high-quality “glass” lenses for tack-sharp photographs.

• Avoid high ISOs, if possible. When shooting on a tripod in dimlight, keep the ISO at the lowest possible setting. If hand-holding indim light, it may be impossible to get the photograph without usinga higher ISO.

• Because the LCD on the camera is an unreliable gauge of focus, usethe zoom feature to examine the photograph detail for focus.

• Out-of-camera image manipulation can help with focus, but theoriginal image must remain without modification. In fact, thereis a trend to avoid or not even allow software manipulation of photos.

• Hand-holding the camera in anything but direct sunlight increasesthe likelihood of obtaining out-of-focus photographs. A trick is touse the camera’s burst function.

• In hand-holding situations, bracing the camera against somethingcan steady it sufficiently to obtain sharp photographs.

The Correct Forensic Exposure

Exposure refers to the amount of light entering the camera and hasbeen defined as “the duration and amount of light needed to create animage.”3 The basic unit of exposure is the “stop,” where one stop is theequivalent of doubling or halving the amount of light entering the cam-era, which the photographer controls by adjusting the aperture, shutterspeed settings on the camera, or the ISO (International Organization forStandardization). Controlling exposure allows the photographer to obtainperfect forensic perspective.

Aperture: Forensic Photographic Gold

Aperture refers to the size of thehole through which light enters thecamera. This opening to the camera’sexternal world is covered by amechanical shutter that closes morequickly or more slowly (shutterspeed) and limits the time the digitalsensor is exposed to the light. Thecamera settings used to adjust thesize of the hole are called f-stops orf/numbers. Aperture settings are theforensic equivalent of photographicgold because aperture is the first consideration when photographing any-thing at the crime scene. This is because it controls the perspective: whatis in focus or depth of field (DOF).

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Figure 10.1: Aperture Basics

Table 10.1: Forensic Photographic Types

Categoryof Photograph Reason for the Photograph

Establishing Continuous, overlapping perspective of the scene. Scales are notnecessary. Maximum depth of field (f/11 to f/22).

Midrange Capture immediate surroundings and relative relationship of potentiallyprobative evidence. Scales may be necessary depending on subject. If so,photographs should be taken with and without scales. Maximum depth offield (f/8 to f/16).

Close-up or Captures detail of potentially probative evidence. Photographs should bemicrophotography taken with and without scales. Generally, a shallow depth of field (f/1.4

to f/4). Weiss characterizes close-up images as a way to capture evidencein relation to its discovered location.

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Figure 10.2: Illustration of Lens Focal Length

Telling the Scene’s Story: Importance of Aperture

The forensic photographer must decide what should be in focus. By choos-ing the aperture first, the photographer is not only determining what shouldbe in focus in his photography, but he is also making a thoroughly consid-ered decision after critically evaluating the scene. This is active archiving.

Shutter Speed

The role of the shutter is to shut off the light getting to the digital sensor,which it does by opening and closing the cover (diaphragm) over the aper-ture. The speed at which this happens determines the specific amount oflight entering the camera. This is actually a measure of how long the shut-ter is open. Like aperture settings (f-stops), shutter speeds follow a standardscale: 1/8000, 1/4000, 1/2000, 1/1000, 1/500, 1/250, 1/125, and so on,where the denominator refers to fractions of a second. Shutter speed is aconcern for photographers because the longer the shutter is open, thelonger the photographer has to hold the camera still. A shutter speed of1/60 (1/30 or 1/15 if the camera has vibration control) is usually necessary.

ISO

The ISO is a measure of the digital sensor’s sensitivity to light. The higherthe ISO, the more sensitive the sensor is to light. For forensic work, thepractical implication is that larger ISO numbers offer an opportunity toshoot in dim light. The trade-off is that, as the ISO numbers increase, theresulting photograph begins to deteriorate. In practical terms, this results inless opportunity to “blow up” the photograph.

Focal Length: Lenses

The focal length has nothing to do with exposure. It is lens dependent, andfor practical applications it refers to how far an object must be from the lensfor it to fill the viewfinder. The “normal” zoom lens—18 to 55 mm (close towhat the human eye perceives)—is in the middle of the range. This lens is

appropriate for mid-range photographs. The wide-angle zoom (12 to 24 mm)allows the photographer to capture more of the scene without moving backand is appropriate for establishing photographs. Also, it may be appropriatein a tight space. The telephoto lens (55 to 200 mm) captures detail fartheraway from the object photographed and has value for outdoor scenes formidrange/establishing (55 mm setting) photographs and midrange (200 mm)setting. They have some value as an alternative to a MACRO lens for close-ups, although the quality is not nearly as good. A useful lens for close-upphotographs is a fixed focal length 60 mm MACRO lens.

Metering

Cameras need to know how much light is being reflected from an object todecide on an appropriate exposure. Modern digital cameras accomplish thisby using TTL (through-the-lens) metering systems, which means the camerameasures the amount of light that is reflected from an object. However, TTLsystems often force the camera into making poor decisions; the result isover- or underexposed photographs. Modern digital SLR cameras typicallygive the photographer choices to tell the camera how to measure the lighthitting the digital sensor: Examples include matrix, center-weighted, andspot. For most forensic shooting situations, the matrix setting gives themost consistent results. However, situations exist that require the photogra-pher to use a different type of metering, such as in backlit situations.

White Balance (WB)

There is nothing more frustrating than sorting through a series of crimescene photographs with a blue cast. The cause is an improper white balance.The white balance setting on digital SLR cameras tells the camera how to“see” white. Actually, WB settings allow the camera to produce accurate col-ors under a variety of lighting conditions.4 All color has what is known as acolor temperature, measured in degrees Kelvin. If the photographer choosesthe incorrect color temperature, the colors present in the photograph can be“off,” which is unacceptable. Luckily, modern digital cameras typicallyinclude a menu of either icons or described situations available.5

For most scenes, the WB should be set for the particular area of the sceneof interest for that specific perspective. The linked area would be pho-tographed at a later time. Some digital cameras allow WB bracketing, whichmeans the photographer can shoot a sequence of three images. One framewill be at the WB setting chosen by the photographer, one will be slightlywarmer and the other slightly cooler. This gives the photographer a betterchance of accurately capturing colors. Another way of setting white balanceis to shoot the photograph using the RAW file setting and then altering thewhite balance using appropriate photo-editing software. This cannot be donefor JPEG photographs.

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Figure 10.3:Capturing the Perfect Forensic Photograph: A Roadmap

© Shutterstock.com

Taking the Perfect Forensic Photograph

The process for acquiring properly exposed, forensically relevant pho-tographs begins with choosing the proper perspective, which means care-ful consideration before pressing the shutter release button. This is whenthe scene scientist/investigator decides what the scene is going to say tofuture investigators.

The second step is to examine the lighting at the scene (incandescent, out-doors, fluorescent, or other). Then set the white balance (WB) appropriately.Next, move the selector knob to the “A,” aperture priority. This is when youconsider the type of photograph you need: establishing, midrange, or close-up—and hence the depth-of-field required. After setting the aperture, thecamera decides shutter speed based on the reflected light entering the TTLmetering system. The resulting photograph tells the photographer whetherthe camera is reading the scene properly.

Examine the WB and exposure on the photograph in the viewfinder. Ifthey appear perfect, you’re finished and can move on to the next photo-graph. This is rarely the case, and capturing that perfect photograph willrequire some final adjustments to the exposure. When the WB and apertureare set, turn the selector knob to “M” or “manual” priority. Change the

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shutter speed until you get the best exposure. This might require takingseveral photographs. The final step is to bracket the shots at different shut-ter speeds and/or the WB.

Forensic Aspects of Photography

Although forensic photography is simply the application of photographicprinciples to forensic situations, there are rules that are inviolate.

• The first photograph in a series must have an incident photo-graphic worksheet or cover sheet. This is usually a gray card with colored stripes, the case number, date, location, and name ofthe photographer.

• Photographs must be listed in a photo log.

• Scenes must be preserved using establishing, midrange, and close-up photographs.

• Close-up photographs must include one with scales and the otherwithout scales.

• Illumination (metering) should be appropriate to capture impressionevidence detail.

• There should be a continuity of overlapping establishing photographs.

• Tripods should be used for all photographs where the camera mustbe steady: close-ups, certain midrange photos, Luminol (BlueStarTM)photography, and dim light situations.

• The camera (and tripod) should be perpendicular to the plane inwhich the evidence lies and horizontal (parallel).

• Scales must be in the same plane as the object photographed.

• Photographs should be taken before and after each on-scene manip-ulation (enhancement attempts) of evidence.

• The pop-up flash on the camera should never be used except inspecific circumstances.

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Questions1. What is forensic archiving?

2. What is the relationship between the aperture setting and the depth offield (DOF)?

3. Name three camera settings that determine exposure.

4. In order to take the perfect forensic photograph, what should be yourfirst consideration?

a. Determining the appropriate forensic perspective and then adjustingthe aperture setting appropriately.

b. Taking a photograph on the “auto” or point-and-shoot mode of thecamera and then changing aperture and shutter speeds accordingly.

c. Consider the white balance of the area being photographed and thenchange it accordingly.


Other Books of InterestKelby, Scott. The Digital Photography Book. Vol. 1, p. 12. Berkeley, CA:Pearson Education/Peachpit Press, 2006.

Lezano, Daniel. The Photography Bible: A Complete Guide for the 21stCentury Photographer. P. 40. Cincinnati, OH: David and CharlesPublishers, 2008.

Lecture 10 Notes1. Lezano, Daniel. The Photography Bible: A Complete Guide for the 21st Century

Photographer. P. 40. Cincinnati, OH: David and Charles Publishers, 2008.

2. Kelby, Scott. The Digital Photography Book. Vol. 1. P. 12. Berkeley, CA: PearsonEducation/Peachpit Press, 2006.

3. Nikon, Inc. The Nikon Guide to Digital Photography with the D40 Digital Camera. P. 45.Melville, NY: Nikon Inc., USA, 2006.

4. Kelby, Scott. The Digital Photography Book. Vol. 1. P. 12. Berkeley, CA: PearsonEducation/Peachpit Press, 2006.

5. Nikon, Inc. The Nikon Guide to Digital Photography with the D40 Digital Camera. P. 49.Melville, NY: Nikon Inc., USA, 2006.

Forensic procedures dictate that three types of photographs are madeat crime scenes. And capturing the evidentiary information requires fol-lowing critical forensic procedures.

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Lecture 11

Forensic Photographic Technique: Archiving Crime Types

The Suggested Reading for this lecture is Robert C. Shaler’s Crime Scene Forensics: A Scientific Method Approach, chapter 6: “ThePrinciples of Forensic Photography.”

The forensic archivist must be an expert in not only recognizing evidenceat the crime scene but in capturing it in three principle photographic types:establishing, midrange, and close-ups.

Establishing: Overview or Overall Photographs

Establishing photographs are overviews of the scene and are the first stageof archiving the scene. These are designed to depict the general orientationof the scene and should be shot in sequence so that the end result is aseries of overlapping images. Establishing shots should be taken before andafter evidence markers are in place. The reason is to capture first the unal-tered scene and then show the relationship of marked evidence. It is alsoappropriate for mid-range photographs to have evidence markers in place.

The relative position of all evidence, even evidence not yet found, shouldbe in the photograph unless obscured. Schematics exist for establishingshots designed to capture the essence of the scene. These are designed tominimize mistakes, but careful and critical thought is necessary beforeembarking on a photographic campaign.

Establishing photographs means aiming for maximum DOF. This meansusing an appropriate lens (illustrated in Figure 11.1). For this scene, thefocus should be approximately ten feet into the scene (in front of where thebody lies). Focusing on the body may bring other areas of the scene out offocus. As an establishing shot, this photograph is not just about the body,but the relationship of the body to everything in the specific area. Thehatched arrow in the middle of the schematic illustrates the first choice forfocus. Experimental photographs will tell the photographer where the opti-mal focal point should be.

The illustration suggests using a shorter focal length; however, too short afocal length can cause distortion problems. If the photographer uses a wide-angle lens, the resulting photographs can appear “off.” There are circum-stances, however, where the photographer needs a wide-angle lens to getthe entire scene in a single shot.

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Figure 11.1: Where to Focus at the Scene

Midrange Photographs

The next step is to “get closer” to the evidence so the evidence’s relativeposition in a specific area of the scene is clearer. For example, the establish-ing shot may show a knife lying some distance from the deceased’s rightarm. It is critical to pinpoint the knife’s position perfectly, which mayrequire multiple perspectives. A bloodstain pattern on a wall should be cap-tured in midrange photographs, and the entire pattern captured.

Establishing photographs tell an observer that the bloodstain pattern is pre-sent, but the midrange shot captures the size and shape of the entire pat-tern—evidence marker and scales in place. Subsequent close-up photo -graphs will detail specific droplets of interest: directionality, size, those hav-ing included air bubbles, and pieces of tissue. Bloodstain patterns shouldnever be photographed using a flash.

Scales are not necessary for midrange photographs, but there are excep-tions, such as the discussed bloodstain pattern.

Close-up PhotographsEvidence having detail with criminalistic or investigative value—knifelength and width—must be preserved photographically. An important cate-gory of evidence that should be included is impression or pattern evi-dence: fingerprints, footwear impressions, tire tracks, and tool marks. Thefirst photograph is taken without scales and the second with scales. Allclose-ups should be shot using a tripod. Close-up photographs by definitiondo not have DOF because they are usually taken of evidence on planar sur-faces. There are instances, however, where surfaces are curved (finger-prints on doorknobs).

Figure 11.3: The Interaction of Light with Matter

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IlluminationFor photographers, light is either controlled or uncontrolled. In a controlledsetting, the photographer controls the type, the amount, and the location ofthe light entering the camera. An uncontrolled environment uses primarilyambient light.

The illustration in Figure11.2 shows where toplace the light sourcedepending on the depthof the impression.Impressions having ashallow texture require a near floor-level lightsource. Less of anoblique light source fordeeper 3D impressionswill usually suffice.

Filters

Filters are useful to darken, make warmer or cooler, or eliminate glare inphotographs. Some specifically block or pass visible, ultraviolet, or infraredlight, and some darken a photograph a specific number of stops. From aforensic perspective, most filters have limited utility. However, some areimportant depending on the subject photographed.

Other filters are used in conjunction with alternate light sources. Specificwavelengths of light interact with matter in basic ways: The light isabsorbed, transmitted, or reflected. Sometimes the light absorbs energy andthen loses it in the form of a photon (light) called fluorescence. However,because of the light reflected from the object, the fluorescence may not be

Figure 11.2: Oblique Lighting

visible to the naked eye or the camera. Losing the reflected light meansblocking it so that it never makes it to the camera. This is accomplishedusing barrier filters.

Camera Positions

Camera positioning is critical to capturing the evidence correctly. If thescene photograph is distorted or the lens not perpendicular to the plane inwhich the evidence lies, direct comparisons with exemplar evidence mightbe compromised. All photographs must be taken parallel (horizontal) to theplane and the lens must be perpendicular (vertical) to the evidence.

Scales

Close-up and some midrangephotographs must have scales inat least one photograph. Properlyaligning the scales along thewidth and length of the mostimportant aspects of the evidenceis critical. Placing a single scalealong one side of a fingerprint oron one side of a knife is not cor-rect. Each side must have a scale.

Photographic Archiving ofCommon Scene Scenarios

Photography is only one aspect of the investigative jigsaw puzzle, and itmust fit into the logic of the investigation without hindering the flow of theinvestigation. So scheduling is critical. If one part of the process happensout of phase, such as photography, the investigation can be inefficient andthe team may miss critical evidence.

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Figure 11.4: Positioning the Camera Relative to the Evidence Photographed

Figure 11.5: Incorrect Placementand Use of Scales

© Robert C. Shaler

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Vehicular Accidents

Vehicular accidents are complicated, are almost always outdoors, and oftenoccur in high-traffic areas. Archiving these scenes is as much a public ser-vice as an insurance issue because the possibility of criminal as well as civillawsuits looms large. The following is a list of accident scene subjects that, ifpresent, should be captured.*

In addition to macroscene elements—vehicles, vehicle impact points,blood, debris, and skid marks—it is important to portray those intangiblecharacteristics endemic to accident scenes: the sightlines of the driversand witnesses and obstructions that might have hindered them. Trafficcontrols and the relative location of signals, yield, and stop signs are alsoimportant. Sight-line photographs should be taken at drivers’ eye level.The exact heights at which the photographs were taken must be recorded,and if estimates are needed, these must be recorded.

Accidents can occur because of factors outside the control of the driver:glare from sunlight, darkness, and bad weather. Capturing this informationis critical, too.

Homicide ScenesIndoor homicide scenes often display signs of activity that carry across sev-eral rooms. This should be captured in a continuum as though filming thescene while the crime is taking place.

Investigators often treat the body as the most important part of the scene,but this notion is far from correct. The medical examiner/coroner needs toconduct a competent medico-legal investigation and the scene is an impor-tant aspect of that investigation. But waiting before moving and transport-ing the body is not a big deal. It is more important to conduct the investiga-tion logically, systematically, and completely; photographing the body is onlyone part of the archiving process. Eventually the body becomes the forensicphotographer’s focal point. And there are logical procedures for document-ing the body and its immediate environment.

Special Photographic Situations

The forensic archivist regularly encounters challenging circumstances.Those that can be predicted require some discussion.

Night and Low-Light Scenes

At night or in dark situations, exposure poses a problem because the lightthe camera needs to record an image is either minimal or not available. Ifthe ISO and aperture/shutter combinations do not compensate for thediminished light, an artificial source (flash or special technique such aspainting with light or light fill) or extended exposure times are necessary.

The flash unit on top of the camera should never be used to photograph evi-dence directly except in extraordinary situations. The camera’s on-board

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flash can be too bright and can wash out the detail of the evidence or oblit-erate it entirely. That is not to imply that flash photography has no forensicvalue. Its value comes when the evidence and the background on which itlies are essentially the same color; that is, there is too little contrast.

Painting with Light

Painting with light is a technique for illuminating large outdoor scenes. Thephotographer sets the camera on a tripod to stabilize it, opens the shutter to“B” (bulb), and keeps it open while moving a flash unit around the area pho-tographed. A long synchronization cord is necessary to allow the attached flashto illuminate up to 150 feet.

Slaves

Slaves are nonattached flash units that trigger when another flash goes off.Using slaves is similar to painting with light except that the photographerplaces individual flash units in strategically located positions at the scene.When the on-board flash (or off-camera-attached flash) goes off, the lighttriggers the slaves to flash simultaneously. In small areas at indoor scenesand small outdoor scenes, this technique may be preferable to the paintingwith light technique.

Impression Evidence Photography

Impression evidence photography is about creating contrast between thesurface on which the impression lies and the texture of the impression.Generally, photographing impressions involves the same technique as thatused to find them at crime scenes—oblique lighting. The positioning of thelight dictates how well the texture of the evidence will appear in the photo-graph. As with all close-up forensic photography, photographs should betaken with and without scales and should capture the length and width ofthe entire impression. This is an experimental procedure, so there will betrial and error before obtaining the appropriate photographs. An off-cameraattachable flash should be held first at an angle of approximately tendegrees from the perpendicular, but the specific situation may require a dif-ferent angle to obtain acceptable results. Flash is recommended, but sinceflash can create shadows, the scale should always be placed along the longedge and short edges of the impression.

For 3D impressions, photography is particularly important as a backup tocasting, and three aspects of the impression must be captured: 1) anoverview of the impression, 2) scales capturing the dimensions of theimpressions on two sides, and 3) the detail of the impression.

Since most 3D impressions occur outdoors, other concerns are also in play,such as temperature and sunlight. This requires employing tricks to captureas much of the impression detail as possible.

Close-up Photography

The forensic relevance of close-up photographs is twofold:

1. Establish measurements ofthe item.

2. Preserve critical detail ofthe evidence as examined.

Several commonly occurringtypes of evidence require close-up photographs: weapons, fin-gerprints, other impression evi-dence (footwear impressions,cartridge cases, or other items),and blood.

Image in the Viewfinder

The image of the photograph in the viewfinder must take up as much ofthe viewing area as possible.

Scales

Scales and their position are critical and must be included in close-up photographs. Close-up photographs are taken with and without scales.

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© Shutterstock.com

Figure 11.6: LCD Viewfinder Imageof Close-up Photograph

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Questions1. At the scene for establishing shots, what is a rule of thumb for where to

focus initially in order to capture the maximum amount of information in focus?

2. In which of the following is it mandatory to use scales in photographs?

a. Establishing photos

b. Midrange photos

c. Close-up photos

d. None of the above


Other Books of InterestBlitzer, Herbert L., and Jack Jacobia. Forensic Digital Imaging andPhotography. Burlington, MA: Academic Press, 2002.

Kelby, Scott. Chapter 1. “Pro Tips for Getting Really Sharp Photos.” TheDigital Photography Book. Vol. 1, p. 1. Berkeley, CA: PearsonEducation/Peachpit Press, 2006.


Redsicker, David R. The Practical Methodology of Forensic Photography.2nd ed. Boca Raton, FL: CRC Press, 2001.

Staggs, Steven. Crime Scene and Evidence Photographer’s Guide.Wildomar, CA: Staggs Publishing, 1997.

Lecture 11 Notes*Miller, Larry S., and Richard T. McEvoy, Jr. Police Photography. 6th ed. Burlington, MA:Anderson Publishing, 2006. Pp. 135–168.

Case FilesSometimes referred to as a case jacket, the case file contains the officialrecord of the investigation. The case file is where one finds investigators’reports, sketches, worksheets, written notes, audio and photographic CDs,printed photographs, investigative leads, and witness statements. It iswhere investigators new to a case can review what had been done in theoriginal investigation.

The location, virtual or otherwise, where the work product of thecrime scene unit’s investigative activity is maintained.

The definition above makes it clear that the case file can be maintained ina paper or an electronic format. It can reside in a file cabinet, cardboardboxes in the basement of the police station, or on a backed-up computer’shard drive. Regardless, the files must be secure. If they were originally in apaper format, they should be converted to an electronic one that is non-cor-ruptible. Electronic case files must be backed-up and the original files pro-tected from hackers.

Pages in the case file are numbered sequentially. If there are fifty-twopages, the first page would be either “1 of 52” or “1/52,” with new addi-tions added sequentially. A page added out of sequence at a later timereceives a number indicating it was placed into the case file at that loca-tion. Corrections to page 135 should be inserted after page 135 andlabeled “135A.” New pages are added at the end of the case file.

WorksheetsGiven the increased importance of electronic media, the term “work-sheets” seems archaic. Still, worksheets fall into four basic categories:audio, handwritten notes, filled-out forms, and sketches. Worksheets areanything relevant to the investigation that is filled out, prepared, or record-ed. These include investigative notes or thoughts and anything digitallyrecorded or typed into a computer. They include draft and final sketches.

Lecture 12

The Written Record: Case Files, Scene Sketches,and Worksheets

The Suggested Reading for this lecture is Robert C. Shaler’s Crime SceneForensics: A Scientific Method Approach, chapter 7: “Case Files,Worksheets, Notes, and Sketches.”

The official written record of the scene investigation is kept in a casefile that includes the written, audio, and digital records of the sceneinvestigative effort.

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FormsForms represent a critical part ofthe official record. Each investiga-tive agency has its own forms. Someagencies have detailed forms andothers do not. Common formsemployed include chain-of-custody,scene response, photographic, mea-surement logs, and quality assuranceforms. They must be filled out com-pletely, including case numbers, theinitials of the person filling out theform, and other specified informa-tion. If the form has multiple pages,each page should be filled out andnumbered sequentially.

Examples of forms used in thePennsylvania State University crimescene investigation course are shown in Figure 12.1. The “Case ContactLog” is a record of individuals who were at the scene and specific commentsabout why they were there or other relevant information about them.

The “Scene Response Log” is a record of those crime scene unit teammembers at the scene. The form records the times they arrived and leftthe scene. If the team responded to the scene more than once, the teamleader would fill out a separate form each day the team was at the scene.

The forms in Figure 12.2document the control of evi-dence at the scene andwhere it goes after leavingthe scene (for example, thepolice property room or thecrime laboratory). The mostimportant form is the “Chainof Custody” form, because itis the signature record of theevidence’s integrity. Thecrime scene team leader’sresponsibility is to ensurethat each item of evidencecollected has a documentedsignature history from thetime it is collected and pack-aged at the scene to where itis eventually transported.

Figure 12.1: Forms: Case Contact andScene Response Logs

Forms standardize

the work product.

Figure 12.2: Evidence Control Forms

The signature trail must remain intact until the evidence is eventuallydestroyed, and there must be a record of that, too. A break in that history—known as a break in the chain—compromises the integrity of the evidenceand leaves it at risk of not being admissible in a court of law.

The top part of the “Chain of Custody” form has the item number (givenat the scene) and the description of each item collected at the scene. Thebottom part shows the transfer of evidence of those involved in the transfer.

The form on the bottom of Figure 12.2 is an example of an inventory logof items collected at the scene. It captures the sample ID (item number,which becomes the item ID entered on the Chain of Custody form) andinformation about the item.

Additional forms are also used to capture the record of the crime sceneunit’s activity at the scene. For example, Figure 12.3 shows two forms usedfor documenting the collection ofimpression evidence. Each formcaptures critical information: theitem number (the same number inthe chain of custody form), theobject on which the print (impres-sion) was found and the methodused to visualize it (unless it was apatent print), the location wherethe object was at the scene, theperson who collected the impres-sion, the method of how it was col-lected, and the person who pho-tographed the impression and themethod used.

Mistakes

Humans fill out forms, which means that mistakes are expected. Correc -tions are necessary and they have a specific format.

• Run a single line through the mistake.

• Write the correct information above the mistake.

• Place your initials and the date of the correction next to or abovethe correction.

• Never obliterate or white-out a mistake.

Sketches

Before there was photography, there was sketching, and it remains anessential skill. Sketches lay out the scene in a way that neither pho-tographs nor video can. They provide an overview and the precise and/orrelative location of evidence. It has been suggested* that sketching the

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Figure 12.3: Impression Evidence Forms

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crime scene involves two separate actions: one artistic and the second ana-lytical, which pinpoints the relative location of the elements of the scene.Gardner considers the latter analytical because it requires measurement ofthe boundaries and the elements at the scene, a process similar to map-ping. Although no true analysis is involved, forensic sketching for the pur-poses is defined as follows:

A marriage of drawing and making measurements of crime sceneelements, the final rendering of which is a perspective that rendersthe scene understandable to the lay public and provides informationto investigators.

Typically, sketching occurs twice.Rough sketches (drafts) are done con-temporaneously with the scene investi-gation, and they are discoverable as evi-dence in a legal proceeding. A finalsketch, that is, a final rendering, is acleaned-up version of the rough sketch;it, too, is discoverable.

Sketching is among the first activitiesat the scene, and it occurs contempo-raneously with photographing andsearching for and protecting fragileevidence. One of the first decisionsthe team leader has to make is where to begin the sketch. He has to makecertain that the entire scene, including each critical item, is captured with-out interrupting the investigative process.

Determining how to sketch important areas of the scene depends on theteam leader’s perceived importance of each item of evidence. There areitems that require precise placement and others that do not. Sketches pro-vide an overview of the scene and the relative relationship of evidence;they complement photo and video archiving by clarifying confusing details.They enhance investigators’ recall of the scene details when it comes timeto testify in court or to review cold cases. They help to orient the scene lay-out to scientists/investigators, attorneys, the judge, and the jury.

Sketching most effectively involves two people working together because itmakes the process easier and faster: one measures, the other draws andrecords the data. Both sketches, the rough and the final, should include thefollowing information.

• Address (place of sketch).

• Date and time.

• Temperature and weather conditions (sunny, cloudy, raining).

• North and south indicators.

A crime scene sketch rendered in a 3DCAD program from a rough drawing madeat the scene.

© The CAD Zone

• Name of sketchers: individuals who did the sketch.

• Case number.

• Notation of whether the sketch is rough or final.

• A legend to capture information in the sketch.

There are different ways to make a sketch. One of the early methods wasto use graph paper for both the rough and final sketches. The detail in thefinal sketch can use templates of furniture, bodies, weapons, and other evi-dence. Computer programs and 3D imaging systems speed the final sketchafter entering measurement data: 3D imaging systems collect thousands ofmeasurements in 360 degrees using infrared lasers. These measurementscan be turned into 3D drawings using dedicated software. The problemwith these systems is that they are slow and can restrict movement in thescene to areas not being imaged. Computer aided design (CAD) programs,some of which have been adapted for crime scene work, can convert roughmeasurements into final, polished sketches.

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© Shutterstock.com

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Questions1. What is a case file?

2. How do you correct mistakes on forensic documents?

a. Obliterate the mistake and write the correction above the obliteration.

b. Mask the mistake with White-OutTM and write the correction over the mask.

c. Draw a single line through the mistake and write the correction above.

d. Draw a single line through the mistake. Write the correction and putyour initials above the cross-out.

e. Draw a single line through the mistake and then write the correction,your initials, and the date above the cross-out.

3. What is the importance of crime scene sketches?


Other Books of InterestFish, Jacqueline T., Larry S. Miller, and Michael C. Braswell. Chapter 3:“Documenting the Crime Scene.” Crime Scene Investigation. Bethesda,MD: LexisNexis/Anderson Publishing, 2007.

Fisher, Barry A.J. Chapter 5: “Processing the Crime Scene.” Techniquesof Crime Scene Investigation. 7th ed. Boca Raton, FL: CRC Press, LLC, 2004.

Lecture 12 Notes* Gardner, Ross M. Practical Crime Scene Investigation and Reconstruction. Boca Raton, FL:CRC Press, 2004

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Sketch Types

Over the years, investigators have devised various ways to sketch a scene.Many of these have names, which for our purposes are considered“named” sketches.

The Plan Sketch

The plan sketch is simply anoverview of the scene, and it isthe simplest scene sketch for ajury to understand. It is essen-tially required for all crimescenes. It gives an accurateoverview of the scene and therelative location of evidenceobserved. The rough plan sketchis made at the scene and is notdrawn to scale. The final sketchis prepared at a later time andmust be drawn to scale. A partialplan sketch can be made of theindividual components of thescene, such as walls with bulletholes or bloodstain patterns,because they are not typicallyconsidered part of the floor plan per se.

Cross Projection or Exploded Sketch

The cross projection sketch is essentially a flattened view of the scene,much like a box with its sides, top, and bottom pressed into a singleplane. These are useful for scenes where the walls and ceilings haveimportant probative evidence. They are appropriate for rooms but not for an entire building.

How do crime scene investigators archive the scene using appropri-ate sketching and measuring methods, whether the scene is indooror outdoor?

Lecture 13

Sketch Types and Pinpointing Evidence at the Scene

The Suggested Reading for this lecture is Robert C. Shaler’s Crime Scene Forensics: A Scientific Method Approach, chapter 7: “Case Files,Worksheets, Notes, and Sketches.”

Figure 13.1: Student’s Indoor Plan Sketch

Figure 13.2: Cross Projection Sketch

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Elevation Sketch

Elevation sketches are, in essence, plan sketches of areas of a scene. Theydocument a side view of one part of a scene, such as a wall or a ceiling,that might have important visual evidence. Measurements should berecorded on the sketch to indicate the exact location and, in the case of abloodstain pattern, its size. An elevation sketch might also show the posi-tion of bullet defects. If measurements make the sketch too cluttered, thenthey should be recorded in a separate log.

Perspective Sketch: 3D Rendering of the Scene

These sketches depict the three-dimensional aspects of the scene. Thistype of sketch requires artistic skills, if done free-hand, or 3D software.

Outdoor Sketches

Outdoor sketches are essentially plan sketches and thus are typicallyoverviews of the crime scene. They illustrate the location of evidence suchas the debris field and body locations after an airliner crash.

Measuring the Scene

Determining the dimensions of the scene and pinpointing evidence is acritical aspect of sketching. It is commonly accomplished using tape mea-sures, infrared laser 3D imaging instrumentation, or wheel measuringdevices that “click off” measurements as one rolls a wheel along theperimeter of a large area. The measurements themselves must be preciseenough to allow someone to return to the scene at a later date and under-stand the placement of evidence in its original location. Measurementsare also critical for investigators who need to rework the case after itturns cold.

The most accurate and also the most tedious measuring method is triangula-tion. Such preciseness should be reserved for measuring critically probativeevidence, such as a weapon lying on the floor. Other items at the scene donot need to be fixed so precisely, except to note their location relative to afixed object at the scene. The size of the piece of furniture fixes its location.

Measuring outdoor scenes employs the same principles as those describedbelow for fixing the location of evidence indoors. The main difference canbe the size of the scene.

Locating Objects at the Scene

Locating objects at a scene is typically done using the following measuringmethods or variations of these.

Triangulation Method

Triangulation is accomplishedby measuring the object rela-tive to two fixed, immovablepoints at the scene. In Figure13.3, the “X” is a knife and“Y” is a cigarette butt. Points“A” and “B” are corners atopposite ends of a wall. Thedistance between them is mea-sured. These are the fixedpoints used in the triangulationmethod. The distances from “X”and “Y” to both “A” and “B” fix these items at the scene.

Baseline Method

In this method, an object is locatedto a perpendicular dropped to a line,such as a wall. The distance frompoint “B” to where the perpendicu-lar falls on the line between “A”and “B” and the distance from thatpoint to the evidence fixes the loca-tion of that evidence.

A variation, the modified baselinemethod, employs angles from a fixedobject instead of the perpendicular.Here, instead of using the perpen-dicular, the angle from the evidenceto the reference line “A” and “B” ismeasured, as is the distance from the evidence to the line.

Figure 13.3: Triangulation Methodof Measuring a Scene

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Figure 13.4: Baseline Methodof Measuring a Scene

Polar Coordinate Method

Another variation of the modified baseline method is known as the polarcoordinate method. This uses a virtual line fixed by cardinal directions:north, south, east, or west. The initial fixed point can be a GPS location ora fixed object. A virtual baseline fixes the location of evidence in conjunc-tion with triangulation or baseline measurements made to items of evi-dence. So whether the measurement runs from the object to be measuredto a virtual or real line, or whether it is 90 degrees or some other angle,doesn’t matter. The object is fixed at the scene. Typically an outdoormethod, its major attributes are listed below.

• Evidence scattered over open areas (airline crashes; bombing scenes)• Need direct line-of-sight; cannot be hindered (woods or other objects)• Uses surveying techniques> Total Station or other 3D imaging systems > GPS coordinates> Laser or IR measuring devices

• Start at single datum point (GPS; triangulation to fixed point)

Measuring Outdoor Scenes

Outdoor scene measurements are best accomplished by combining thepolar coordinate method with triangulation and/or the baseline methods.An issue with outdoor scenes concerns finding fixed points of referencebecause they are not always readily apparent or available.

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Figure 13.5: Baseline Method of Measuring an Outdoor Scene

In Figure 13.6, the first point is fixed by triangulating to a point in the scenefrom a house. Subsequent measurements of evidence at the scene are madefrom a virtual line (actually a tape measure laid on the ground) through thescene, where the direction of the line is a cardinal designation: N, S, E, or W.Measurements off that line can be made using either triangulation, the base-line method, or combinations of triangulation and baseline methods.

Measuring Outdoor Scenes Using a Rose Compass or Azimuth Board

The Rose Compass is an alternative method for measuring items at an out-door scene. An example illustrating how to use the Compass Rose/AzimuthBoard is illustrated in Figure 13.7. The Rose Compass is useful for large,open areas, but it can also be used for more closed areas.

• Fix the compass to the ground by staking the center hole with anappropriate dowel and the four corner holes.

• Triangulate middle hole and one corner hole to two fixed objects atthe scene (or GPS coordinates if appropriate fixed objects are notavailable) so that the compass can be returned to its original loca-tion at some future date.

• Run a line (tape measure) from the center hole (secured by anappropriate stake) to each item of evidence.

• Measure the distance from the compass to the item of evidence andrecord the value in a log. Also record the degree the tape passesover. Since the Rose Compass is marked in degrees (0 to 360) theprecise location of each item of evidence is fixed as “X” number ofinches (or feet) at “Y” degrees from the center of the Rose Compass.

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Figure 13.6: Triangulation Method of Measuring an Outdoor Scene

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Figure 13.8: Wooded Scene and Evidence Located at the Scene

© Robert C. Shaler

Figure 13.7: Using the Rose Compass to Measure an Outdoor Scene

An example of students investigating a wooded scene is shown in Figures13.7 and 13.8. The student crime scene teams were faced with searchingthe scene for evidence of a serial killer. After completing the search andmarking evidence, the students measured the scene. They chose the RoseCompass because it gave them a fixed reference point at the scene. In choos-ing the Rose Compass, they subsequently realized that they had a problem:trees and bushes at the scene interfered with the straight line measure-ments. They solved the problem by using the Rose Compass in two differentlocations after bisecting the area. The photograph on the left in Figure 13.8shows what the scene looked like before the investigation began. The photo-graph on the right shows evidence in a plastic bag they found.

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Questions1. What is the difference between triangulation and baseline methods of

measuring a scene?

2. What is a plan sketch?

3. Which is the best way to sketch and measure an outdoor scene?

a. Use a polar-coordinate method and a triangulationmeasurement method.

b. Use a plan sketch and a triangulation measurement method.

c. Use a polar-coordinate method and a combination of triangulation andbaseline measurement methods.

d. None of the above.


Other Books of InterestFish, Jacqueline T., Larry S. Miller, and Michael C. Braswell. Chapter 3:“Documenting the Crime Scene.” Crime Scene Investigation. Bethesda,MD: LexisNexis/Anderson Publishing, 2007.

Fisher, Barry A.J. Chapter 5: “Processing the Crime Scene.” Techniquesof Crime Scene Investigation. 7th ed. Boca Raton, FL: CRC Press, LLC, 2004.

Fingerprints are fragile, and the techniques used to visualize them can eas-ily damage friction ridge detail. For example, powder dusting is commonlyemployed, but a heavy or a not-so-gentle technique can affect the quality ofthe resulting print, as can overdusting.1 The responsibility of the crimescene team leader is to preserve the original print detail as it was left at thescene, so using new or novel techniques without employing a scientificapproach is risky.

A Reasoned, Scientific Approach

Scientists and investigators have spent decades devising methods to devel-op and enhance fingerprints at scenes and in latent print laboratories. Thetarget of these investigations, the components of the print residue, hasbeen the subject of intense scientific inquiry. The result has culminated in amenu of print-development methods.

Modern scene investigators and latent print scientists understand that thecurrent print-development paradigm is surface driven, with each methodhaving its particular dogmatic approach: Porous surfaces have a preferred,menu-driven group of methods, as do the nonporous.

On-Scene Printing: Menu-Driven versus Logic-Based Approaches

The fingerprint paradigm is a menu-driven approach designed for nonsci-entists to know when to employ certain methods to minimize errors. Thisapproach has merits born from a wealth of experience and success. Butshould there have been more successes? Certainly! How many latent finger-prints at those crimes were treated improperly or how many unsuccessfulattempts had there been versus those that were successful?

Fingerprint development methods have laboratory and on-scene applica-tions; most are laboratory-based. Certainly, there are reasons for develop-ing/enhancing prints in the field, and whether this is the best course ofaction depends on the dynamics of the investigation. Should the evidencebe collected, packaged, and taken to the laboratory? Will a delay impair thetimeline of the investigation?

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An intelligent approach to fingerprinting at the scene is necessary todesign an effective latent print development strategy.

Lecture 14

Fingerprinting: The Intellectual Ingredients

The Suggested Reading for this lecture is Robert C. Shaler’s Crime SceneForensics: A Scientific Method Approach, chapter 9: “Fingerprints atthe Crime Scene: The Intellectual Ingredients.”

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There are always items that cannot be easily collected: the door jamb or awindow that was the entry point to the scene. At an outdoor crime scene,it might be better to collect and package all transferrable printable evidenceand take it to the laboratory, especially if the weather is deteriorating andprotecting the evidence at the scene is impossible.

Another consideration is time. Allscenes have time constraints, but ifprocessing the scene quickly is criti-cal, then regardless of the logic fordeveloping prints there, trans-portable fingerprint evidence shouldgo to the laboratory.

If the decision is to process printson-scene, there are important con-siderations: surface, resources,environment, age of the print,amount and quality of print residuepresent, scene investigator’s knowl-edge, experience, and the technolo-gy available and its limitations. Most investigators choose dusting, believingthis to be the best, easiest, and quickest way to obtain results. For a givencircumstance, that may be true. But no print development should occur untilthe nuances of the scene have been properly considered.

Surface Characteristics

The fingerprint development paradigm considers first the surfaces: porous,nonporous, or semiporous. Even these are simplistic because other consid-erations are often not spelled out. For example, one concern is how a par-ticular surface has been protected (was it painted using matte, semi-gloss,or gloss paint?). Or is it one of the newer finishes with texture? If textured,how much depth is there?

Porosity is another consideration. Another is color. What developmentmethods are applicable if it is dark or light colored? Which technology isbest suited giving the most contrast: physical methods, chemical methods,imaging technology, or topology acquisition? Other surface nuances are com-mon, such as the best way to approach fingerprints on cornered surfaces.

Environmental Conditions and the Age of the PrintThe length of time a print has been exposed to an environment shouldaffect decisions concerning a development strategy. No one questions thatheat, humidity, pollution, UV radiation, dust, and time affect print quality. Ifit is hot and humid, dusting or Super Glue fuming may have the best

Figure 14.1: On-Scene Considerations fora Fingerprint Development Strategy

chance of success. If the temperature is moderate (say 50oF) and the humid-ity is between 20 and 90 percent, the same may be true. If it is winter andthe humidity is low and the house overheated, the print could be dry(dehydrated print residue) and unresponsive to traditional dusting or evenSuper Glue fuming. Studies designed to explore the Super Glue fumingreaction in eccrine prints have shown that lactate in the residue is the ini-tiator of the Super Glue fuming reaction. If lactate is gone, whether becauseof excess heat (greater than 50oC) or from UV radiation, Super Glue fumingwill not work.2

The Tools

The next decision concerns the tools necessary and available to do the jobproperly. This decision balances what can be done at the scene versus thetools available in the laboratory. Laboratory work is usually done in a morecontrolled environment, which should lead to better results. Never sacrificequality for expediency without a top-notch reason.

Resources

Success may well depend on available resources. If the crime scene unitcan only dust, alternative strategies are nearly nonexistent. If the unit canonly dust at the scene but has additional capabilities at the latent print labo-ratory, there is an alternative.

Technology and Its Limitations

All technology has limitations. However, most scene investigators have lit-tle understanding of the science underlying the technology. This means thatthere is little understanding of when the science will be successful andwhen it will not. Most applications of science in the field are employed inroutine situations for which the technology had been developed. However,circumstances crop up where applying a particular technique may not workas planned, if at all. Such failure might not be understood by the investiga-tor, and the inclination is to blame failure on the quality of the print ratherthan an inappropriately applied technology.

Logic

Locating fingerprints leading to an eventual successful development and liftis as much an intellectual exercise as it is physical, and having the besttechnology does not guarantee success. The scene scientist/investigatormust know where and when to employ technology. Successfully finding pro-bative prints involves a myriad of skills, the most important being logic,experience, and knowledge. Understanding the scene environment and thenature of the crime gives experience, critical thinking, and thinking out-of-the-box a reasoned approach to an effective strategy. This is the only formu-la for success.

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Knowledge of the Science

Understanding which techniques are available for developing fingerprintsand how they work in specific circumstances is also critical. Knowing andunderstanding the dynamics of crime scene investigation are additionalingredients for understanding how evidence “talks” and why this translatesinto knowing the likely location of fingerprints.

Experience

Experienced scene scientists/investigators are better at developing andfinding prints than a novice or a student. Experience also rules when itcomes to employing science and using technology.

Critical Thinking

This is the process of assessing and digesting information the scene pre-sents and then distilling it so probative evidence pops out and speaks:

• An open window may or may not be related, and if the former,developed fingerprints on the windowsill are irrelevant.

• The area of a struggle will say that someone fell onto the floor andthat there might be usable prints.

• Bloodstains on the floor in the kitchen might be significant.

• Eating utensils might have prints that can be important.

• Bloodstains in the kitchen might be irrelevant, if they occurredbecause the deceased suffered a lacerated finger while choppingonions—check the body for recent finger wounds (the ME mightdecide this is a defensive wound).

• A partially chopped onion on the cutting board, some of it mixedwith a drop of blood, and a bloody knife lying on the floor shouldscream “No relevance.”

• A bloodstain out of context from other blood at the scene shouldalso scream: “Perp injured.” Certainly the blood itself is a criticalpiece of evidence, but it is likely not the only evidence in that area.

Out-of-the-Box Reasoning

This is different from critical thinking, albeit an extension of it. Few indi-viduals process information like this because it is a process of thinking criti-cally and then translating that into an investigative strategy that leadsdirectly to the most probative evidence. It is also a process of marryingseemingly unrelated information and developing a hypothesis of what hap-pened. The “lone, out-of-place” bloodstain mentioned above is an example.Innovative thinking involves more than experience. It is, in fact, a mindthat works on a different level, one that creates order from chaos. Theseindividuals “see” evidentiary links that others miss. It is a gift.

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Questions1. Explain the specific scene considerations that the scene investigator

should consider before embarking on a fingerprint development strategy.

2. Explain the environmental considerations the scene investigator shouldconsider before embarking on a fingerprint development strategy.


Other Books of InterestChampod, Christophe, Chris Lennard, Pierre Margot, and Milutin Stoilovic.Chapter 4: “Fingerprint Detection Techniques.” Pp. 136–138.Fingerprints and Other Ridge Skin Impressions. Boca Raton, FL: CRCPress, 2004.

Lee, Henry C., and R.E. Gaensslen. Chapter 4: “Methods of LatentFingerprint Development.” Pp. 108–113. Advances in FingerprintTechnology. 2nd ed. Eds. Henry C. Lee and R.E. Gaensslen. Boca Raton,FL: CRC Press, 2004.

Olsen, Robert D., Sr. “Chapter V: Latent Fingerprint Powder Techniques.”Pp. 209–240. Scott’s Fingerprint Mechanics. Springfield, IL: Charles C.Thomas Publisher, 1978.

Lecture 14 Notes1. James, Jonathan D., Anthony Pounds, and Brian Wilshire. “Obliteration of Latent Prints.”

Journal of Forensic Science. 36(5), 1991, pp. 1376–1386.

2. De Paoli, G., S.A. Lewis Sr., E.L. Schuette, L.A. Lewis, R.M. Connaster, and T. Farkas.“Photo- and Thermal-degradation Studies of Select Eccrine Fingerprint Constituents.”Journal of Forensic Science. 55(4), 2010, pp. 962–969.

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COURSE MATERIALS

Suggested Reading

Shaler, Robert C. Crime Scene Forensics: A Scientific Method Approach.New York: Taylor & Francis, 2011.

Other Books of Interest

Blitzer, Herbert L., and Jack Jacobia. Forensic Digital Imaging andPhotography. Burlington, MA: Academic Press, 2002.

Champod, Christophe, Chris Lennard, Pierre Margot, and Milutin Stoilovic.Fingerprints and Other Ridge Skin Impressions. Boca Raton, FL: CRCPress, 2004.

Chisum, W. Jerry, and Brent E. Turvey, eds. Crime Reconstruction.Burlington, MA: Academic Press, 2007.

Fish, Jacqueline T., Larry S. Miller, and Michael C. Braswell. Crime SceneInvestigation. Bethesda, MD: LexisNexis/Anderson Publishing, 2007.

Fisher, Barry A.J. Techniques of Crime Scene Investigation. 7th ed. BocaRaton, FL: CRC Press, LLC, 2004.

Gardner, Ross M. Practical Crime Scene Processing and Investigation. BocaRaton, FL: CRC Press, 2007.

Geberth, Vernon J. Practical Homicide Investigation: Tactics, Procedures,and Forensic Techniques. 4th ed. Boca Raton, FL: CRC Press, 2006.

Inman, Keith, and Norah Rudin. Principles and Practice of Criminalistics:The Profession of Forensic Science. Boca Raton, FL: CRC Press, 2000.

Kelby, Scott. The Digital Photography Book. Vol. 1, p. 12. Berkeley, CA:Pearson Education/Peachpit Press, 2006.

Lee, Henry C., and R.E. Gaensslen. Advances in Fingerprint Technology.2nd ed. Eds. Henry C. Lee and R.E. Gaensslen. Boca Raton, FL: CRCPress, 2004.

Lee, Henry C., Timothy Palmbach, and Marilyn T. Miller. Henry Lee’sCrime Scene Handbook. Burlington, MA: Elsevier Academic Press, 2005.


Olsen, Robert D., Sr. Scott’s Fingerprint Mechanics. Springfield, IL: CharlesC. Thomas Publisher, 1978.

Redsicker, David R. The Practical Methodology of Forensic Photography.2nd ed. Boca Raton, FL: CRC Press, 2001.

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Saferstein, Richard. Criminalistics: An Introduction to Forensic Science.9th ed. Old Tappan, NJ: Pearson-Prentice Hall, 2004.

Shaler, Robert C. Who They Were: Inside the World Trade Center DNAStory: The Unprecedented Effort to Identify the Missing. New York: FreePress, 2005.

Staggs, Steven. Crime Scene and Evidence Photographer’s Guide.Wildomar, CA: Staggs Publishing, 1997.

These books are available online through www.modernscholar.com or by calling Recorded Books at 1-800-636-3399.

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THE LAW OF THE LAND: A History of the Supreme CourtProfessor Kermit L. Hall—Utah State University

The Supreme Court of the United States represents our most unusual andleast understood branch of government. Unlike the other branches, the highcourt marches to an overtly legal drummer, one that demands there be casesand controversies, there be lawyers who function as adversaries, and that allarguments be made in open court. In the end, the Court is a living, breathinginstitution whose members have as often as not either been vilified or praisedfor both the quality of their legal reasoning and the political impact of theirdecisions. This course is about the high court, its justices, its traditions, and,most importantly, its impact on the American Republic.

FUNDAMENTAL CASES: The Twentieth-Century CourtroomBattles That Changed Our NationProfessor Alan M. Dershowitz

The courtroom trial has fascinated human beings from the beginning ofrecorded history. Trials provide a unique window into American history and thesense of America’s enduring commitment to law. What’s a great trial? Peoplewill often say the trial of the moment. But those trials are often not enduring.Esteemed professor and civil liberties lawyer Alan M. Dershowitz looks athistory through the prism of several important trials. Each of these trialspresents a dramatic snapshot of the nation at the time in which it occurred.

PHILOSOPHY AND THE LAW: How Judges ReasonProfessor Stephen Mathis—Wheaton College

Do judges deduce their decisions from legal rules and principles, or do theydecide cases based on what is fair given the facts at hand? The latter view, heldby Legal Realists, serves as the starting point for Professor Stephen Mathis’ eye-opening look at how judges reason. In this compelling lecture series, theesteemed professor addresses such issues as whether the law is distinct frommorality. Professor Mathis also attempts to identify a view that offers guidanceto judges in deciding cases, and one that will provide the tools people need toevaluate the interpretations and decisions judges make.

DETECTIVE FICTION: From Victorian Sleuths to the PresentProfessor M. Lee Alexander—The College of William and Mary

From its own mysterious origins, through the Victorian sleuths and the“Golden Age” of the genre (the 1920s through the 1940s), and to the presentday, detective fiction, mysteries, and spy thrillers have consistently topped best-seller lists around the world. Professor M. Lee Alexander provides listenerswith a lively discussion of groundbreaking authors from Edgar Allan Poe andArthur Conan Doyle to Agatha Christie, Ian Fleming, and modern writers suchas Nevada Barr and Jonathan Kellerman.

These courses are available online through www.modernscholar.com or by calling Recorded Books at 1-800-636-3399.

RECORDED BOOKSThe Modern Scholar offers the following courses in law, law enforcement, andcrime fiction.

Documents

Crime Scene Investigation Philosophy, Practice, And Science Part 1