Unit 1 Introduction

1A. Forensic Science is the study and application of science to legal matters.

1. “Forensic” comes from the Latin word forensis which means forum (where there was judicial hearings).

2. Forensics science = criminalistics3. Forensic scientists study different types of evidence recovered from

crime scenes.a. Testify in court as an expert witness

i. Presents data, evaluates evidence and renders an impartial opinion

b. Performs scientific research and to train others.4. The following are disciplines used in forensics

a. Chemistryb. Biologyc. Firearmsd. Document examinatione. Photographyf. Toxicology – study of poisonsg. Fingerprintsh. Polygraphy – the study of lie detectioni. Pathology – study of unexplained/unusual deathj. Anthropology – study of human kindk. Psychiatry – study of mental disordersl. Odontology – study of teeth and dental recordsm. Engineeringn. Computer technologyo. Geology – study of the Earth’s structure

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p. Environmental scienceq. Entomology- study of insectsr. Physics

1B. The Legal System

1. There are several different types f law in the U.S. criminal justice system.

1. Statutory Law – written lawa. The law on the books.b. Made by congress.c. Based on the Constitution

2. Civil Law – deals with relationships between individualsa. Marriage, divorce, wills, property, contractsb. Assigns a blamec. Needs a “preponderance” of evidence to convictd. Punishable by fines (generally)

3. Criminal Law – deals with offenses against and individual that are deemed offensive to society

a. State would bring charges against the accused.b. Misdemeanor – minor crimes like small thefts, minor

assaults(threat of bodily harm)/battery (bodily harm), possession of small amounts of drugs.

c. Felony - major crimes like murder, armed robbery, dealing drugs

d. Needs to be deemed guilty beyond a reasonable doubt.e. Punishable by fines, incarceration, community service, life in

prison and capital punishment

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4. Equity Law - remedial or preventativea. Restraining orders or injunctions (orders to start doing

something or to stop doing something)5. Public Law – regulation and enforcement of rights6. Administrative Law – I.R.S., social security administration, military

1C. The steps in pursuing justice.

2. Crime is committed3. Crime discovered4. Police investigate5. Crime scene documented and searched for evidence6. Information gathered and given to prosecutor7. Arrest warrant is issued if there is enough evidence for probable

cause. 5% of arrests are with warrents8. Arrest, Maranda rights, fingerprinted, photographed9. Preliminary hearing – bail, pleas for misdemeanor, trial worthy10. Trial date

a. 50% of those arrested are convicted1. 25% of those convicted go to jail

11. Observation – what a person perceives using his/her senses.a. Investigators must observe interpret and report clearly.b. To collect evidence without making judgements (until later)c. Perception – interpreting information received from the senses

1. It is not always accurate People

1. Filter information2. Fill in gaps3. Apply previous knowledge

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12. 2. Observation by witnessesa. Eyewitness – a person who has seen someone or something

and can communicate the facts (info that can be verified).b. Emotional statis influences our ability to observec. Other things that influence observational skills:

1. Whether the person in alone or in a group2. The number of people or animals in the area3. What type of activity was occurring in the area4. How much activity was occurring

d. Eyewitness accounts of a crime scene vary considerably from one another due to: stress, interest, prejudices, personal beliefs, motives, memories fade and concentration

e. Eyewitnesses often give their opinions of what happened instead of the facts.

1. Opinion – personal belief based on judgement rather than on direct knowledge

f. Eyewitness testimony is very powerful and can sway a jury. g. Knowing the shortcomings of eyewitness testimony is

necessary to ensure justice.13. Police officers and investigators

a. Are trained to have good observational skillsb. Are trained to have good analytical skills

1. Ability to identify a problem2. Isolate the component parts3. Organize information4. Establish criteria to evaluate5. Draw appropriate conclusions

c. Are trained in deductive reasoning4

1. Deductive reasoning – deriving the consequences from the facts using a series of logical steps

1D. Evidence

1. Direct evidence – evidence in the form of a statement made under oath

A. Physical evidence – any object or material that is relevant in a crime scene

B. Locard’s principle – there is always an exchange or transfer of material when two objects touch or come into contact.

C. Edmond Locard - 1877 – 1966 French scientist)

2. Indirect evidence – evidence that does not prove a factA. Circumstantial evidence – implies a fact or event.

1. The more circumstantial evidence, the higher probability of a crime.

3. Class evidence – narrows an identity to a group of persons or thingsA. Ex. Blood typing can narrow the lists of sustpects

4. Individualized evidence is evidence that can be traced back to a single source.

A. **The best evidence is the type to be individualized to a single specific source.

5. Good Evidence A. Proves that a crime has been committedB. Corroborates testimonyC. Links a suspect with a victim or crime sceneD. Establishes identityE. Allows reconstruction of events of a crime

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6. 1. The Rules of Evidence – define what is acceptable (admissible) and how it can be used for the jury

A. Relevant 1. It must prove something (probative)2. It must address the issue of a particular crime (material)

B. Reliable Presenter is credible (has credentials and experience)

C. Hearsay is not admissible in criminal court but it is admissible in civil court.

1. Hearsay is information received from other people that one cannot adequately substantiate, rumor

7. 2. Two important legal decisionsA. 1. Fry standard

1. 1923, scientific evidence must be by an expert and have a “general acceptance.”

B. 2. Daubert ruling1. 1993, judges don’t have to go by the Frye standard as long

asa. Scientific theory is testableb. It is subject to peer reviewc. The rate of error is statedd. It follows standardse. There is consideration to acceptance

1E. The crime scene investigation team

1. Police Officers – first to arrive2. CSI investigators – document scene and collect evidence3. Medical examiners – coroners, pathologists, doctors who study dead

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4. Detectives – interview witnesses5. Specialists – entomologists (study bugs), forensic psychologists

(profilers), weapon specialists, etc…

1F. The seven S’s of CSI

1. Securing the scene a. Done by the first responderb. Safety is #1, preserving evidence is #2.

2. Separating the witnesses a. Witnesses must not be allowed to talk to each otherb. Questions to ask the witnesses

i. What crime occurred?ii. When did the crime occur?

iii. Who called in the crime?iv. Who is the victim?v. Can the witness identify the perpetrator?

vi. What did the witness see? Hear? Feel?vii. Where were you when you observed the crime scene?

3. Scanning the scene a. Primary crime scene – where the crime was committed ex. In

the convenience storeb. Secondary crime scene – in some way related to the crime but

not where the accrual crime took place ex. The suspect’s home.4. Seeing the scene

a. CSI examineri. Photograph with and without a measuring stick

ii. Photos from many different angles

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5. Sketching the scene a. Rough sketchesb. All objects must be measured from at least 2 immovable

landmarksc. Includes doors, windows, North, scale to determine sizes

6. Searching for evidence a. Must walk a pattern

i. Back and forth, spiral, grid…ii. Pattern must be systematic – no area is left unsearched

iii. Use of flashlights and forceps (tweezers) is preferred.7. Securing and collecting evidence

a. Proper packaging, sealing and labelingb. Liquids and arson remains should be in airtight containers and

sealed.c. Biological evidence should be in breathable containers to

prevent mold formingd. Evidence should be sealed in another bag with tape and signed

with the collector’s name and date sealed.e. Chain of custody – it’s a record of who has taken, opened,

studied the evidence,i. The whereabouts of the evidence must be recorded at all

timesii. Everyone must keep a written record of when the get the

evidence and the needed it for.f. Evidence Log – includes the case number, item number,

description, name of suspects, victim, date and time of recovery, signature of person recovering evidence, signature of witnesses during collection

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1G Crime Scenes

1. Reconstruction – involves forming a hypothesis of the sequence of events from before the crime was committed through its commission.

2. Staged Crime SceneA. “I was framed!”B. When the evidence doesn’t match the sceneC. Fires are set to cover up other crimesD. Make a murder look like a suicideE. Fake burglary to scam insurance company

3. All deaths are initially treated as homicides

1H Physical Evidence Collection

A. Chain of Custody 1. Mark the evidence with your initials – if not possible, mark

envelope or packing2. Place evidence in the appropriate container

i. Mark with case #, item # and brief description of evidence3. Seal securely to prevent cross-contamination4. Sign the seal (tape) and date it.5. Always sign the chain of custody and date it when transferring6. Transport to laboratory in the appropriate fashion.

B. Packaging of Evidence 1. Clothing in paper sacks or evidence envelopes.2. Over-sized evidence in brown paper, sealed at the edges.3. Place individually wrapped evidence items in the same box.

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4. Remember to put case reports or evidence inventory on the outside of the envelop or box.

5. Biological Evidence Packaging i. Photograph the blood pattern, use a scale (ruler) for a

reference for size.ii. Collect the whole article or use a barely moist swab.

iii. Swab a nearby area to be the “control.”iv. Package in paper to air dry swabs or clothing.v. Keep cool or frozen

vi. Collect known samples for comparison.vii. Check with hospital when needed to ensure collection of

evidence and chain of custody.6. Hairs, Fibers and small items packaging

i. Package carefully by folding in paper and putting into envelopes.

1. Can use sticky side of Post-Its to affix.ii. Collect comparison items.

7. Paint chips from vehicles packaging i. Remove all layers of paint by chipping.

ii. Package all samples in separate, sealed containers (paper or vials).

iii. Label the source of each sample.iv. Collect comparison items.

8. Glass and Plastic evidence packaging i. Collect all evidence from scene.

ii. Package to prevent further breakage and pad the sides to prevent sharp edges from poking through.

iii. Collect glass from possible sources in a separate package.

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iv. Microscopic size fragments are found mostly in shoes and clothes.

1. Put whole item in folded paper and then a well-sealed paper sack.

9. Headlight evidence packaging i. Pack with care to prevent damage to filament to bulb.

ii. Draw a sketch of damage in relation to the car BEFORE removing.

10. Controlled substance packaging i. Usually tested at a scene

ii. Use plastic bags to collect powders.iii. Use glass vials to collect liquids.

1. Do not send in needles or razors.iv. Use paper containers for mushrooms or plants.

11. Toxicology collection and packaging i. Testing urine for drugs

1. Use a urine kit to collect directly into container. Secure lid.

a. Put evidence inside a biohazard bagb. Keep cool, deliver to lab with 24 hours.

2. Testing Blood for alcohola. Use a blood kit.

i. Qualified individual must draw blood.ii. Secure lid.

iii. Put evidence inside a biohazard bagiv. Keep cool but do NOT freeze

12. Firearms collection and packaging i. Bullets

1. Collect all possible in separate paper sacks.11

2. If the bullets are from an autopsy – rinse and allow to air dry

3. Do not put marks on bulletsii. Weapons

1. Record position of the hammer2. Unload and submit ammunition as evidence3. Package weapon in paper 4. Indicate all exams desired for the lab to do

a. Serology, fingerprinting, firing conditions and serial number recognition

iii. Gunshot Residue can be tested on people1. Hands within 3 hours2. Face within 8 hours3. Nasal cavity within 48 hours

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Unit 2 Hair

A. Hair is a filament composed mostly of Keratin.1. Keratin is a tough, fibrous protein (made from amino acids)2. Hair is produced in a bulb-shaped pocket in the skin – called a

Hair follicle.

a. Sebum - fatty lubricant matter secreted by sebaceous glands of the skin

b. Sebaceous gland – microscopic exocrine glands in the skinB. Why do we have hair ? What is its function?

1. Hair protects against extreme temperatures.2. Hair protects against harmful ultraviolet sun rays.3. Maybe Camouflage

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4. To help prevent heat loss through the head.a. 80% of heat loss is through the head

5. Attraction to the opposite sex.6. Nose and ear hair filter dust.7. Eyebrows shield our eyes from excessive sunlight an blocks

sweatC. Attributes of Hair

1. There are about 100,000 scalp hairs2. 80-90% are actively growing.3. About 100 hairs fall out every day.4. Hair is common to humans.5. Hair is durable and is resistant to physical and chemical

breakdown.6. Hair clings to thins like fabrics.7. Hair cannot determine sex or age of the person it came from.8. We can get DNA from hair in the root and the hair shaft.

D. Morphology (form and structure) of the human hair shaft. It has three distinct parts.

1. Cuticle – the clear, outside covering of the haira. It protects the inside layers of the hair from temperature

and humidity changesb. Made of tough, overlapping scalesc. Human hair has a finer patternd. Human hair does not show much variation in the pattern

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2. Cortex – the thickest, middle part of the hair shafta. It is made of Keratin moleculesb. It has pigment granules which give hair its color )black,

brown, yellow or red)c. Gray/white hair doesn’t have pigment granules

3. Medulla – is the inside part of the hair shafta. It is a row of cells running along the center of the hair –

like a canalb. It may appear dark or transparent.c. There are different types of human medulla forms

d. Asian and American Indian hair usually has a continuous medulla.

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