Anthropological Analysis of bones

Objectives: The student should be able to:1) Identify and name major bones, and bone structures, in the human

body.2) Compare bone sizes and be able to estimate the gender and size of

the person.3) Make accurate measurements and calculate proportions for

appropriate size ranges of other bones in the same person.

Activities:1) Identify the bone by comparing its shape to known samples from

the intact skeleton.2) Make measurements of length and girth of each of the bones.3) Determine approximate size of the person by proportions of bone

lengths.4) Determine the gender of the person by examination of hip (pelvic)

structure.

I. Historical developmentA. Scientists

1. Bertillon’s anthropometry a. Body measurements to distinguish between people

2. Galton’s distinctiveness of fingerprints3. Lattes categorized ABO blood groups4. Goddard determined if bullet fired by a particular gun

B. FBI under Hoover made large-scale effort in forensics1. Extend to state and local authorities

II. Crime laboratoryA. Basic services

1. Physical science unita. Uses chemistry, physics and geologyb. Identify drugsc. Soil and mineral analysesd. Examine trace physical evidence

2. Biological unita. DNA analysisb. Blood and body fluid identificationc. Comparison of hairs and fibersd. Botanical comparisons

3. Firearms unit

a. Examine guns, previously-fired bullets, cartridge cases, shells and ammunition

b. Clothes and objects examined to determine type of gun and position of shooter

4. Photography unita. Examines and records physical evidenceb. Digital imagingc. Infrared, X-ray, ultraviolet photographyd. Create exhibits for courtrooms

B. Full-service1. Toxicology unit

a. Study body fluids and organs to determine presence or absence of drugs

i. Ex. Blood-alcoholb. Latent fingerprinting

i. Hidden fingerprint analysesc. Polygraph unitd. Voiceprint analyses

i. Use sound spectrograph to identify voicese. Evidence-collection unit

i. Protect and preserve evidence from crime sceneC. Other forensic services

1. Forensic pathologya. Investigation of sudden, violent or unexplained deathsb. Usually a coronerc. Questions sought to answer:

i. Who is victimii. What injuries are presentiii. When did the injuries occuriv. Why and how were the injuries produced

d. Autopsy to establish cause of deathe. Classification of deaths

i. Naturalii. Homicideiii. Suicideiv. Accidentv. Undetermined

f. Estimating time of deathi. Rigor mortis

Within 24 hours but gone after 36 hours Muscles become rigid

ii. Livor mortis Settling of blood to parts closest to ground Can be used to see if body has been moved

iii. Algor mortis Body temperature cools 1 to 11/2

0 F per

houriv. Potassium levels in ocular fluid

Cells within eye release Potassium after death

2. Forensic anthropologya. Examination of human skeletal remainsb. Determine age, approximate age, sex, race, skeletal injury

3. Forensic entomologya. Can be used to estimate time of death

4. Forensic psychiatrya. Human behavior and legal proceedings are examinedb. See if people are competent to stand trial or make a willc. Develop profiles of criminals

5. Forensic engineeringa. Fires, explosions, structural failures, accidents

III. Court cases involving use of forensics in judicial proceedingsA. Frye v. United States

1. Decision of admission of procedures, techniques and principles depends on its general acceptance by a “meaningful segment” of the scientific community

B. Daubert v. Merrell Dow Pharmaceutical, Inc1. Frye standard not absolute and evidence can be admitted even if

not general acceptance by a “meaningful segment” of the scientific community

2. Made trial judges responsible for determining acceptancea. Guidelines

i. Scientific technique or theory can be testedii. If it has been subject to peer reviewiii. Its potential rate of erroriv. Standards controlling the technique’s operationv. Widespread acceptance in scientific community

b. Allows for admission of new techniques unique to solving new problems

IV. Processing the crime sceneA. Physical evidence

1. All objects that a crime has been committed2. All objects that provide link between crime and victim3. All objects that provide link between crime and its perpetrator

B. Securing crime scene1. First officer that arrives must secure scene2. Lead investigator will develop plan to document scene

C. Photograph evidence while it is unaltered1. If objects moved then pictures may not be admitted as evidence

a. If moved must be noted in report2. Pictures of entire scene including points of exit and entry

3. Surrounding areas where important events occurred before or after crime

4. If indoors all wall areas photographed and adjacent rooms5. If body then photos of body position and location relative to entire

scenea. Close-ups to show injuries and weaponsb. Surface beneath body after it has been removed

6. Each item at scene is photographed to show position relative to entire scene

a. Then close-ups to show details of itselfb. Include ruler or something to show size

7. Videotaping where one records and one narrates as go through area8. Note: photography shows detail better than video

D. Sketches1. Rough sketch shows dimensions of scene and location of all

objectsa. Create a legendb. Objects are located by two fixed points like wallsc. Compass pointing north

2. Finished sketch is prepared with craftsman’s toolsE. Notes

1. Detailed description of scene with location of physical evidence found

2. Must be detailed because coming back to it in months or years3. Record time evidence found and by whom

a. Also need who and how it was packed and marked by4. Tape recording can also be useful5. Video allows for photo and notes at once but must be transcribed

eventually

CRIME SCENE PROCESSING – SCALED DIAGRAMS

BACKGROUND: Students have learned about securing a crime scene, search patterns in a crime scene, and appropriate chains of custody for collected evidence.

PROCEDURE: A mock “crime scene” is set up by the instructor at lab tables. The scene should include several objects (evidence) around the table. The students are to measure the perimeter of the table, make measurements to each of the objects from the perimeter, and make a scaled diagram of this “crime scene”.

Optional Extension: A more realistic mock crime scene can be set up outside, where students must make larger measurements to make their scaled diagrams. They must also use one of the search patterns discussed in class when processing a larger crime scene outside.

EXPECTED OUTCOMES:

Students will be able to make accurate measurements, and transfer these measurements onto a true-scaled diagram.

F. Systematic searches1. Need to be done so that no accusations of cover up arise or

overlook of evidence is incompetence2. Need one person in control to coordinate collection of evidence in

searches3. Spiral, line, grid or quadrant searches may be employed4. Many items are microscopic or undetectable at scene

a. Ex. Hair, blood, fibers from clothesb. May need a broom or special vacuum to use under the

microscope5. Collecting clothing of suspect should be dome6. Scraping under finger nail with toothpick of suspect7. Victim’s autopsy: material sent to lab

a. Clothingb. Fingernail scrapingsc. Hairsd. Bloode. Vaginal, anal, oral swabs for sex linked crimesf. Bullets from body

G. Collecting and packaging evidence1. Purpose is to prevent any changes between time it was removed

and time received at lab2. Nothing should be tampered with until it reaches lab

a. Ex. Not pulling hair off of clothes3. Pill bottles are good for storing small objects4. Manila envelopes are also good5. Clothes must be air dried and stored individually in a paper bag

a. Stops mold and mildew from ruining evidenceH. Maintain chain of custody

1. Scene, transport, lab2. Sign out if removed

I. Controls1. Hair at scene and hair from suspect

J. Crime scene safety1. AIDS and hepatitis B from body fluids2. Officers with contact must have had a hepatitis vaccination

K. Legality1. Can’t search unless a probable cause2. Exceptions:

a. Emergency situationb. Need to prevent immediate loss of evidencec. If made with a lawful arrestd. Consent of all parties

V. Physical evidenceA. Types of physical evidence

1. Blood, semen, saliva2. Documents3. Drugs4. Explosives5. Fibers6. Fingerprints7. Firearms and ammunition8. Glass9. Impressions

10. Organs and physiological fluids11. Paint12. Petroleum products13. Plastic bags14. Plastic, rubber15. Powder residues16. Serial numbers17. Soil and minerals18. Tool marks19. Vehicle lights20. Wood and other vegetative matter

B. Identification1. Determine what type of chemical or substance2. Ex. Type of drugs, explosives, or species of a hair3. Steps involved

a. Design systematic analysis that will always test for that substance

b. Testing must eliminate all other possibilitiesc. Some substances require 1 to 10 tests

C. Comparison1. Attempts to establish if two or more objects have a common origin2. Select properties from suspect and control specimens3. Give conclusions as probability4. Two types of characteristics

a. Individual characteristics are substances that are related at almost 100% probability

i. Fingerprints are 1 X 1060 that two people are sameb. Class characteristics

i. Substance can be associated with a group but not individual source

Ex. Blood types1. Can use additional factors in blood

At crime scene, a lot of these can identify suspect

D. Crime scene reconstruction1. Outline of a likely sequence of events2. Done by physical evidence, observations and statements

a. Need medical examiners, forensic scientists and officers 3. Steps to reconstruct

a. Secure sceneb. Preliminary examination of scene

i. Develop hypothesis using naked eye to piece events togetherii. Develop “attack plan” to search the crime scene

c. Go through scene for physical evidenceVI. Physical versus chemical properties

A. Physical describes substance without reference to other substances1. Ex. Mass, density, color

B. Chemical describes behavior of substance when it reacts or combines with another substance

1. Ex. Wood burning, Marquis reagent and heroinC. Properties are usually related to metric system

1. 1 Liter = 1,000 cubic centimeters (cc)a. Or 1 ml = 1cc

2. Metric to English conversions, vice versaD. Physical properties

1. Temperaturea. Melting, boiling, freezing pointsb. 0F, 0C, OK

2. Weight and massa. Weight versus mass

Density

Objectives: The student should be able to:1) Explain what is mean by density.2) Evaluate how atmospheric conditions can alter the density of an

object.3) Determine the volume of an object using multiple methods.4) Calculate density mathematically. D= M / V

Activities:1) The student will calculate the volume regularly shaped objects

using three different methods:a. Measure length * width * heightb. Perform volume displacement using only the graduated

cylinder.c. Perform volume displacement using the overflow cans.

2) Calculate the density using each volume for each object.3) Find percent error between the most (measuring) and least

(overflow can, and volume displacement) methods

b. W = mg3. Density

a. D = M/Vi. Independent of size of material

b. Methods to measure volumec. Must note temperature of gas and liquid because density

changes with temperaturei. Solid more dense than liquid than gas

VII. Physical properties of glassA. Refractive index

1. Light slows when it hits another medium2. Decrease in speed causes light to bend (refraction)

a. Ex. Object at bottom of pool3. Refraction index is ratio of speed of light in vacuum to its speed in

another medium4. Refractive index = velocity of light in vacuum/ velocity in medium

a. Water at 250C index = 1.333 times faster in vacuumi. Means 1.333 times faster in vacuum

5. Dependent on temperature and the frequency of the wavelength of light

a. Use standard wavelength called the sodium D light6. Transparent solid will “disappear” if placed in a liquid with similar

refractive index7. Amorphous solids have atoms arranged randomly so have one

refractive index

8. Crystalline solids have atoms arranged in orderly manner so have two indexes

a. Known as double refractionb. Calcite can be placed on writing and see two of each letter

i. One index is 1.486 and other is 1.658ii. Difference is known as birefringence

Birefringence is .172 Used to classify crystals

9. Dispersion is process of separating light into its colors (wavelengths)

a. PrismB. Comparing glass fragments

1. Can be used to place a suspect at the crime scene2. Structure of glass

a. Amorphous solid b. Composed of silicon oxides mixed with various metal

oxidesi. Glass made when sand is mixed with metal oxides and melted and cooled

Soda added to lower sands melting point and viscosity

Lime is added so the glass will not dissolve in water

Soda-lime glass Addition of metal oxides such as sodium,

calcium, magnesium and aluminumc. Borosilicates use Boron oxide to make glass such as Pyrexd. Tempered glass made by adding stress from rapid heating

and coolingi. It breaks instead of shatters ii. Used in cars

e. Laminated glass contains a piece of plastic between two pieces of ordinary glass

3. Matching glass fragmentsa. Suspect and crime scene fragments fit together means

statistically impossible not to be from same sourceb. Much of glass is usually to fragmented to match

4. Density and refractive index are best properties to examinea. These properties are class characteristicsb. Density can be measured by using the flotation method

i. Control glass added to liquidii. Density of liquid adjusted until control glass suspendediii. Unknown is then added to see if it floats or sinks

c. Refractive index determined by immersion methodi. Glass put into liquid

Refractive indexes

Objectives: The student should be able to:1) Explain what is meant by refractive index.2) Observe and compare refractive indexes of knowns and unknowns in lab.3) Predict what causes the difference in refractive indexes in each of the

samples.4) Recognize the cause of refractive indexes and its effect on different

crime scenes.

Activities:1) Mount a piece of glass in the first trial (sodium chloride crystal in the

second trial) to the microscope slide. 2) Add a drop of the liquid to the top of the glass particle. Record the

distances of the Becke Line (halo) for each substance. Measure if using a ruler in mm. Focus in and out of the plane of the liquid to best see the Becke Line.

ii. Refractive index of liquid adjusted by temperature until a match point is reached

Point when Becke line disappears because both liquid and glass have same refractive index

iii. Hot stage or GRIM 2 used5. If density and refractive values different from suspect and scene

than not from same source6. If same still can’t identify it from one source

a. Must compare results with frequency of occurrence of glass in society

i. Scientist can make a meaningful assessment as to probability that the fragments were at one time from one source

7. Tempered versus non-tempered glassa. Determined by process called annealing

i. Involves slowly heating then cooling glassii. Change in refractive index for tempered is much greater than non-tempered

C. Glass fractures1. Glass bends when force exerted2. If force greater than glass’s elasticity, it fractures3. Penetration of glass leaves typical fracture patterns

a. Radial fracturesb. Concentric fractures

4. Size and shape of hole can’t be sole factor of projectilea. Ex. Small stone throw hard enough leaves similar hole as

bullet

b. Large stone shatters window just like a gun at close rangei. Gun powder left behind id it is a gun

c. Hole from projectile can determine direction it came fromi. Hole is wider at exit side

d. As velocity of bullet decreases the irregularity of shape and surrounding cracks increase

5. Formation of radial linesa. Form on opposite side of penetrating forceb. SEE TOM

D. Collection and preservation of glass evidence1. All glass must be found to increase odds of matching pieces

together from suspect and crime scene2. Must submit all glass samples found on suspect and a sample of

broken glass (control glass) from crime scenea. Control glass should be taken from area closest to point of

breakageb. Glass should be placed in solid containers to avoid further

breakagec. Individually wrap each garment from suspect. Glass

should not be removed from theseVIII. Physical properties of soil

A. Soil characteristics1. Any natural or unnatural item found on or near Earth’s surface

a. Ex. Rocks, minerals, vegetation, glass, paint chips, etc…2. Can link suspect to crime scene based on its transferability3. Comparison of soil can begin with simple observation

a. Color can be used only if samples are dryb. Microscopes allow to see plant and animal remains

4. Minerals can be identified along with their concentrationsa. Mineral is a naturally occurring crystal with definitive

physical properties5. Rocks and minerals used as building materials so can compare

these pieces also6. Density-gradient tube is used to determine density distribution of

soila. Clear tube is filled with liquids of various densities

7. Soil texture can be used to determine type of soilB. Collecting and preserving soil evidence

1. Samples taken at crime scene and at intervals within a 100 yard radius

a. Establishes variation of soil at scene2. Samples should also be collected at all of suspect’s alibi places3. These samples should only include top soil layer because it is only

part transported4. Should be packed in plastic vials and marked to location5. Garments with soil should be individually wrapped in paper bags

6. Clumps of soil should not be broken upIX. Analysis of organic compounds

A. Matter is anything that has mass and occupies spaceB. Element is simplest substance that provides building blocks that compose

matter1. Smallest particle of element and has its property is the atom

C. Compound is two elements joined1. Molecule is smallest unit of a compound

a. Ex. one molecule of the compound CO2

D. Physical states of matter1. Relationship to volume and shape2. Conversion into various states

a. SublimationE. Organic versus inorganic F. Selecting analytical technique

1. First if organic or inorganic2. Qualitative versus quantitative determination

a. Former seeks to identify material onlyb. Second seeks to find % combination of components of

mixtureG. Chromatography is separation and analyses of mixtures of chemical

substances1. Occurs due to the observation that substances partially escape into

environment when dissolved in a liquid or when absorbed on a solid surface

2. Dissolved gas molecules in a liquid will leave and reenter liquid into equilibrium is reached.

a. The higher the solubility of gas in liquid, the more molecules that stay in solution

3. Requires a stationary phase and moving phase in contact with one another

a. If moving air is in contact with stationary water, then gas out of liquid will be pushed along

b. Gas with high solubility will take longer to movei. Allows for identification based on retention time

H. Gas chromatography (GC)1. Separates mixtures based on a stationary liquid phase and a

moving gas phase2. Works well on highly complex mixtures3. Allow for identification and quantification of each compound4. Design of procedure

a. Carrier gas moves through column at a constant ratei. Gas must be inert so it does not react with mixture

b. Mixture injected as liquid into heated port to vaporize itc. This vaporized material is swept through column by carrier

gas

i. Column is filled with a liquidd. Column is continuously heated to keep it as a gase. Substances in mixture with high affinity for liquid phase

will be slow, vice versaf. Long column allows for a complete separation of mixtureg. Each component enters a detector as it emerged from

columni. Records its retention time on a chromatogramii. Compared to a standard to determine type

5. Pyrolysis gas chromatography is used for substances that can’t be directly injected into GC chamber

a. These materials are heated to high temperature so they decompose into numerous gaseous products

b. Then the gas is injected into columnI. High-performance liquid chromatography (HPLC)

1. Advantage is that it can be done at room temperature2. Moving phase is liquid and stationary is fine solid particles3. Liquid carries unknown mixture over particles4. Substances are slowed as it interacts with particles

a. Allows for identification based on retention timeJ. Thin-layer chromatography (TLC)

1. Solid stationary phase and a liquid moving phase2. Sample must be a liquid or solid dissolved in a liquid3. Liquid moves up column picking up unknown mixture4. Compounds that have high affinity for solid do not move as far5. The paper is removed and allowed to dry6. Finding the various compounds requires fluorescence

a. Need an ultraviolet light7. Finding can also be done by spraying chemical on paper to cause

compounds to generate colored spots8. Identification of compounds is then done by comparing it to known

sample

QUESTIONED DOCUMENTS – TLC

BACKGROUND:Students have learned about various methods of analysis, including chromatography. Since expense prohibits high schools from actually performing chromatographic analysis, this lab is intended to show the basics behind such testing.

PROCEDURE:Students are provided with various water-based markers and filter paper. They are to observe and measure how a solvent (water) separates the marker ink into various components, and relate their findings to chromatographic analysis in the “real world”.

EXPECTED OUTCOMES:

Students will perform an activity, which is analogous to chromatography in Forensics Laboratories, and they will increase their skills of measurement and graphing.

K. Electrophoresis1. Separates protein and DNA based on their sizes and charges2. Done by placing samples into wells of a solid gel3. Opposite charges at each side cause sample to move

L. Properties of light1. Electromagnetic spectrum components can be distinguished by

wavelengths or frequencies2. Objects have color due to absorption and reflection of various

wavelengths of light3. Light acts as a wave

a. Wave can be measured by wavelengths (trough to trough)b. Measured by frequency (number of crests passing given

point in a set time)4. Light acts as a photon

a. Higher frequency means more energyb. More energy means more dangerous for humans

M. Spectrophotometry1. Measures the amount of radiation a material absorbs2. Dependent on frequency or wavelength of radiation3. Material can be quantified because the more material the more

radiation it will absorb4. Spectrophotometer

a. Graphs results in form called absorption spectrumb. Radiation sourcec. Monochromator selects single wavelength

d. Holder for samplee. Detector measures unabsorbed radiationf. Graph to make absorption spectrumg. Use of UV as radiation source produces an absorption

spectrum that usually can’t ultimately distinguish ith. Use of infrared produces a complex pattern that can be used

as a chemical’s fingerprintN. Mass spectrometry

1. Coupled with GC to specifically identify a substance2. Each gas component coming from GC passes into spectrometer3. Inside it is collided with electrons4. The collision causes materials to lose electrons and ultimately

become unstable5. This leads to molecular break down6. Each of these smaller fragments can be separated by mass by going

through a magnetic field7. No two substances produce same fragmentation pattern

X. Analysis of inorganic compoundsA. Inorganic analyses is used to identify explosives, paints, metals, etc…B. Analyses can identify if two or more objects come from a similar source

1. Manufactured goods require raw materials from Earth’s crust2. Crust contains various trace elements or impurities at certain

locationsC. Emission spectrum of elements

1. Elements can absorb and emit wavelengths of light2. Allow for emission spectroscopy and atomic absorption

spectrophotometry3. Emission spectrum is the light emitted from a source and is

separated into its colors or frequenciesa. Light from sun or incandescent bulb has an emission

spectrum that is continuousb. Elements produce discontinuous or line spectrum that is

distinctive for that elementi. Must be a gas that is “excited” by high temperature

c. Emission spectrograph obtains and records line spectra of elements

i. Needs means for vaporizing elements to emit light Done by direct electric currents

ii. Component to separate this light Can be done by a prism

iii. Means to record separationd. Substances usually contain more than one element so must

match graph to known patterns of elementse. Used to identify mutilated bullets, paint chips and glass

pieces4. Atomic absorption spectrophotometry

a. Based on principle that elements will absorb same frequencies as it emits when vaporized

b. Specimen is heated to cause it to vaporizec. Specimen is then exposed to radiation source

i. Best if radiation source is made of a discharge tube of same element one is trying to identifyii. Means light only absorbed if sample contains that element

d. A detector sends information to graphing statione. Can detect elements at levels as small as one-trillionth of a

gramD. Origin of emission and absorption spectra

1. Based on energy levels of electrons2. Each element has a specific arrangement of electrons in energy

levels3. Ground state versus excited state4. To move electrons to different levels requires absorption or release

of specific amounts of energya. Thus absorb specific frequency of light and release same

frequency5. Any other amount of energy will have no effect

E. Neutron activation analyses1. Based on principles of isotopes and radiation2. Some isotopes undergo radioactive decay

a. Alpha rays are positively charged particlesb. Beta rays are electrons being emittedc. Gamma rays is a type of powerful electromagnetic

radiation3. Neutron activation analysis bombards material with neutrons

a. The elements in substance will absorb some and immediately decompose releasing radioactivity

b. Each element has a characteristic energy value given off as gamma ray radiation

c. Concentration can be measured by intensity of it gamma ray radiation

i. Direct relationshipd. Identifies trace elements in drugs, poisons, metals, soils,

etc…F. X-ray diffraction

1. Used to identify how elements are combined into molecules2. Works on crystalline solids

a. Most of inorganic material is this type3. X-rays are sent into compound which is reflected off of the atomic

planes of substance4. These diffraction patterns are then recorded on photographic film5. Every compound has its own diffraction pattern

XI. Microscopes in forensicsA. Compound light microscope

1. Mechanical structure supports apparatus2. Optical system

a. Object is reversedb. Transmitted versus reflected illuminationc. Condenser focuses light on specimend. Objectivese. Monocular versus binocularf. Total magnificationg. Resolution limits magnification to no more than 1,000Xh. Field of viewi. Depth of focus

B. Comparison microscope1. Two compound joined by lenses to one binocular unit2. Allows for side-by-side comparisons

C. Stereoscopic microscope1. Allows for three dimensional viewing of object2. Has low magnification3. Image is not reversed

D. Microspectrophotometer1. Combines microscope and spectrophotometer2. Shines various light wavelengths onto specimen during

observationa. Allows for determination of absorption spectrum

E. Electron microscope1. Allows for high magnification and depth of focus2. Beams a wave of electrons onto specimen

a. Causes other electrons to be emitted from elements on surface of specimen

3. Can be used with X-ray analyzer to determine distribution of elements in specimen

XII. Physical properties of hairA. Morphology of hair

1. Class characteristic because not individual specific2. Can be used as strong corroborative evidence3. Structure

a. Grows from hair follicleb. Hair made up of cuticle, cortex and medullac. Cuticle

i. Gives hair resistance to chemical breakdown and retains its structural features

Results in important forensic useii. Overlapping scales always point towards tip end of hairiii. Scale pattern allows for differentiation of species

iv. Study scale by SEM or embedding into soft medium Ex. nail polish or softened vinyl Remove after medium has hardened and

view under microscoped. Cortex is main part of hair

i. Important because it has pigment granules Compare color, shape and distribution

ii. Examine by mounting in a liquid with similar refractive index

Allows for less light to be reflected and light penetrating is optimized

e. Medulla is cellular column running through middle of hairi. Medullary index is how much of diameter of hair the medulla takes up

Humans is less than 1/3, animals more than ½

ii. Medulla can vary even in same individualiii. Shape of medulla is also important

Humans and most animals have cylindrical shape

f. Root produces hair and keep it goingi. Hair growth occurs in three phases

Determine shape and size of root Anagen has hair attached to follicle for

continued growth1. Flame-shaped2. If this hair pulled usually has a piece

of tissue attacheda. DNA analysis can

individualize Catagen has slight continued growth

1. Elongated appearance Telogen is when growth phase ends

1. Club shaped2. Hair will eventually pushed out

causing sheddingB. Identification and comparison of hair

1. Comparison done to see if human hair and to match with suspecta. Difficult because structural features different even with

same individuali. Need many samples from scene and individual

2. Important characteristics include color, intensity of pigment granules, length, diameter, scale structure, medullary index and shape of medullae

3. Comparison microscope should be used4. Can identify dyed and bleached hair

Hair analysis

Objectives: The student should be able to:1) Demonstrate the proper use of a microscope.2) Use the proper techniques for preparing mounted slides of hair

samples.3) Compare the different hair samples.4) Classify the hair samples into groups.5) Predict the suspected source of the hair sample

Activities:1) Review use of the microscope and procedure for preparing mounted

slides.2) Obtain 4 different “unknown” hair samples.3) Prepare and examine each slide of the samples; note color, texture,

condition. 4) Observe the shaft and root of each sample.5) Make a sketch of all the samples, highlighting the unique properties of

each.

a. Roots will be natural color if hair growth after dyingb. Can also identify time since dying

i. Hair grows 1 cm per month5. Examiners can usually determine part of body part hair came from

a. See book for details6. May be able to determine racial origin of hair7. If hair has root tissues still attached can do DNA analysis to

specifically identify individuala. Uses nuclear DNA

8. Currently working on extracting DNA from hair in anagen phase 9. Mitochondrial DNA currently being examined

a. Only passed on from mother to childb. Many copies in each cell

C. Collection of hair evidence1. Need many samples from scene and suspect; about 502. Hairs must come from same area of body

XIII. Physical characteristics of fibers1. Class characteristic because of mass use of fibers2. Natural fibers are generated from natural animal and plant sources

a. Identification and comparison based on color and structural characteristics

b. Cotton is most commoni. Microscopic view shows ribbon like shape with twists at irregular intervals

3. Man made fibersa. Ex Rayon and Nylon

b. Regenerated fibers have parts made from wood or cottonc. Synthetic fibers made solely from chemical polymers

i. Polymers are long-chained molecules created from condensation synthesis of monomers

ii. Starch versus celluloseB. Identification and comparison of man made fibers

1. Compare color and diameter of control and crime scene specimens2. Compare lengthwise striations on surface of some fibers3. Fibers can be broken down into more than two dozen subclasses4. Dyes in fibers allow for a good comparison of specimens

a. Leads to a more individualistic identificationb. Done by Microspectrophotometerc. Can use a chromatographic spectrum to separate dyes

5. Fibers demonstrate a double refraction because its coating polymer forms a crystalline solid

a. Each subclass of fibers has specific index of refraction6. Infrared spectrophotometry can be used because of organic matter

in fibera. Selectively absorbs infrared radiation based on each

subclass of fibers7. Thousands of colors, shape and microscopic appearance can really

serve to narrow down fiber differencesC. Collection of fiber evidence

1. Difficult because usually not visible to naked eye2. Necessary to identify potential carriers of fibers3. Clothing should be wrapped in paper bags4. Fold rugs and linen to ensure fibers will not fall off5. Use tweezers if you find it necessary to pick up a fiber

XIV. Physical properties of paintA. Forensic examination of paint

1. Piece of paint can determine make, model, color and year of car2. Paint is made of pigments, additives held together by a binder3. Auto paint has a variety of coatings which enhances its

identificationa. Electrostatic primer is first applied to stop corrosionb. Primer surface added to hide imperfections

i. Highly pigmentedc. Base coat is the color one sees on a card. Clear coat is non-pigmented to improve appearance and

durabilitye. Evaluation of layered structure can narrow identification

but still a class characteristic4. Various binder formulations in paint5. Finishes are found in hundreds of varieties6. Analyses

a. Gas chromatography creates specific programs

b. Infrared spectrophotometry to distinguish bindersB. Collection of paint evidence

1. Try to keep paint chip intact2. Paint should not be touched by uncovered hands3. If chip is embedded in material than it all should be packaged

together4. Collection of control should e done on an undamaged part

C. Damaged part can show corrosion, new paint or fadingXV. Physical evidence of drugs

A. Drug is any substance that causes a physiological or a psychological affectB. Drug dependency

1. Psychological dependencea. Drugs create sense of well being or escape

i. Narcotics, steroidsb. Can manifest into desire to avoid withdrawal sickness

2. Physical dependencya. Occurs from regular schedule of drug intake

i. Drug effect does not have time to wear offb. Marijuana, LSD, cocaine not proven to have physical

dependency3. Social impact

C. Narcotic drugs1. Misused to represent all illegal drugs2. Painkiller that depresses vital body functions3. Source of lost is from opium

a. From unripe pod of a poppy plantb. Morphine is extract of opiumc. Heroine is derivative of morphine

i. Solubility allows for injection for immediate affect

ii. 35% of drug is heroin; 65% is other material Could be quinine, starch

D. Hallucinogens1. Cause alteration in normal thought process2. Marijuana is an example

a. Comes from cannabis plantb. Consists of mixed leaves with parts of plant’s flower, stem,

seedsc. THC is chemical that gives its property

3. LSD is derived from fungusa. Creates vivid hallucinationsb. User can be prone to flashbacks

4. PCP (angel dust)a. Intake begins with feeling of strength and invulnerabilityb. Followed by depression and tendency to violence

5. Ecstasy

a. Enhances awareness and decreases inhibitionsE. Depressants

1. Alcohol works on CNSa. Affects memory, reaction time and concentration

2. Barbiturates (downers)a. Also act on CNSb. Causes relaxation and sleepinessc. Taken orally and is dangerous if overused

3. Tranquilizers are depressants that don’t affect high order thinking skills

F. “Glue sniffers”1. Immediate feeling of euphoria2. Have slurred speech, double vision, impaired judgment3. Affects CNS as a depressant4. Danger of affecting liver, heart and brain and can cause death

G. Amphetamines (uppers)1. Initial increase in alertness followed by fatigue and appetite loss2. Causes restlessness, apprehension and depression after it wears off3. Taken orally or intravenously4. Strong psychological dependency

H. Cocaine1. From coca plant2. Powerful stimulant to CNS3. Increases alertness and vigor4. Sniffed through nose5. Crack is derivative of cocaine

a. Can be smoked to get affect quickerb. Extremely addictive

6. Both creates euphoria by stimulating pleasure center in brain 7. Euphoria leaves quickly leaving severe depression

I. Anabolic steroids1. Related to male sex hormone testosterone

a. Promotes secondary sex characteristicsb. Accelerates muscle growth

2. Negative effects on liver specificallya. Infertility, lower sex drive, stops bone growthb. Produces severe mood swings

J. Drug control laws1. Medical and legal definitions of drugs differ2. Penalties dependent on amount or percent of drug

a. Important for scientist to distinguish these factorsK. Drug identification

1. Screening tests done first to eliminate 1000’s of substancesa. Put material to color tests

i. Marquis Reagent turns purple for heroin, morphine Orange-brown for amphetamines

ii. Dille-Koppanyi turns violet-blue for barbituratesiii. Duquenois-Levine turns purple for marijuana

Must also be paired with a microscope analysis

1. Leaves have hair in shape of “bear claws”

iv. Van Urk turns blue-purple for LSDv. Scott Test turns blue for cocaine

2. Second phase pinpoints exact substancea. Done by a confirmation test

i. Any single test that can identify a substance3. Microcrystalline tests

a. Chemical added to drug causes formation of crystals that can seen with microscope

b. Drugs have specific crystal patterns and sizesc. More specific than color testsd. Do not have to separate drug from diluents

4. Chromatography can be used to identify drugsa. TLC and gas chromatography are bestb. Can be made more useful if used with mass spectrometry

5. Spectrophotometrya. Infrared is one of a few tests to specifically identify drugb. Requires the substance to be pure so many preliminary

stepsL. Collection and preservation of drug evidence

1. Does not require major complications2. Make sure packaged and labeled properly3. Place volatile solvents into air tight bag4. Helpful to scientist if investigator can give background information

related to drug’s identityXVI. Forensic toxicology

A. Forensic toxicology is to detect and isolate drugs in body to determine their affects on the body and behavior

B. Effects of alcohol1. Affect CNS2. First affect nerve functions in forebrain3. Increase consumption affects nerves in central and rear portions

C. Alcohol in body1. Moves into bloodstream via stomach and small intestines2. Becomes distributed uniformly in watery portions of body

a. If no blood in dead body, can still test 3. Body rids by:

a. Oxidation into carbon dioxide and water in liveri. Enzyme is alcohol dehydrogenase

b. Excretion occurs through breath, urine, sweati. Here the alcohol is unchanged

4. Concentration in body can be determined by:a. Direct chemical analysis of bloodb. Measuring content of breath and relating to blood-alcohol

concentrationi. Determined by Henry’s Lawii. Fixed ratio of volatile compound in air and its concentration in liquid

D. Breath-test instruments1. Design

a. Breathing into mouthpiece sends air to an ampouleb. Alcohol causes chemicals to react ultimately destroying

potassium dichromatei. More alcohol less potassium dichromate

c. This means it cannot absorb as much light d. More light passing through, the more alcohole. Works like a spectrophotometerf. Standard ampoule used to “zero” scaleg. Fuel cell tests alcohol by oxidizing the alcohol in one’s

breathi. Creates a current proportional to amount of alcohol in body

E. Field sobriety tests include a series of psychophysical tests1. One-leg stand, alphabet, etc…

F. Collection and preservation of blood1. Must antiseptically carried out blood withdrawal

a. Prevents claims of contamination of sample2. Anticoagulant added to prevent clotting3. Preservative added to decrease growth of microorganisms4. Blood stored in refrigerator5. All prevents decline in alcohol concentrations in blood6. Collection of blood in dead body requires several samples over

entire bodya. Due to formation of ethyl alcohol production from bacteria

G. Role of toxicologist1. Must identify toxins and drugs from a small sample of blood2. Difficult because concentrations much smaller than found in pills

or powders3. Difficult because body metabolizes material to form metabolites

a. Heroin quickly changed to morphineb. Morphine binds to carbohydrates before excretion

4. Helpful if connection to victim’s symptoms or method of death5. Need input from investigator, medical examiner and physician6. Dead body allows medical examiner to decide which biological

samples to send to lab7. Living person must get samples of blood and urine

H. Toxicological techniques

1. First step is to remove toxins and drugs from biological materiala. Done by dissolving sample into waterb. Changing its pH allows for extraction of various

toxins/drugs2. Screening done to see if specimen contains a drug

a. Allows for examination of large number of specimens for a wide variety of tests

b. Can use TLC, gas chromatography (GC), immunoassayi. Immunoassay dependent on specific antibody reaction to drugs

ii. Allows for detection of very small drug concentrations

3. Confirmation test fortifies screening testa. Use GC and mass spectrophotometry

4. Heavy metals (arsenic, lead) can be identified a. Dissolve body fluid or tissue in HClb. If a copper strip is added and turns silvery, heavy metals

presentc. Confirm and identify specific type by absorption

spectrophotometry5. Carbon monoxide combines with hemoglobin preventing oxygen

from being carried to bodya. Concentration in blood done by:

i. Spectrophotometersii. Blood can be treated to release CO

Then measured by gas chromatographyI. Need to determine how drug concentration will affect an individual

1. Depends on sex, age, past use2. Two or more drugs may have synergistic affects

XVII. Arson and explosionsA. Chemistry of fire

1. Oxidation is the addition of oxygen to a substancea. Methane consumption reactionb. Necessary for fire or explosion

2. Combustion will not occur unless activation energy is reacheda. Usually accomplished through sufficient heatb. Lit match and gasoline has enoughc. Oxygen and methane alone does not

3. Production of fire occurs only when material is in gas phasea. Wood will not combust until enough heat to decompose

solid into vapori. Pyrolysis is chemical breakdown of solid

b. Flashpoint is lowest temperature in which substance gives off enough vapor to support combustion

c. Still requires a much higher temperature to start combustion

4. Heat of combustion reaction is usually sufficient to keep it going5. Spontaneous combustion is fire that is caused by natural heat

sourcea. Bacteria living on hay can generate enough heat

6. Explosives undergo rapid exergonic reactions that produce large quantities of gas

a. Requires oxidizing agent other than oxygen because it can’t get to gas fast enough to produce explosion

B. Most arson fires started with accelerants1. Petroleum-based2. Gasoline or kerosene are examples3. Evaporate quickly after fire so must investigate scene quickly

C. Primary focus of search is to find origin of fire1. May find multiple separate fires2. May find “streamers” used to spread the fire

a. Ex. Trail of gasoline3. Also important to look for signs of breaking and entering and theft4. Since fire moves upward, origin likely at lowest point with intense

characteristics of burning5. Flammable liquids flow to lowest point so more severe burning on

floor may mean an accelerant6. More burning at bottom of furniture than top may also mean

accelerant7. Look for accelerant in porous material8. Vapor detector can screen material for presence of accelerant

D. Collection and preservation of arson evidence1. Need 2-3 quarts of ash near point of origin2. Collection of evidence should include all porous materials thought

to have flammable residues3. Material must be packaged in airtight containers to stop

evaporation4. Need substrate control for each specimen collected

a. Sample of similar but uncontaminated specimenb. Done to ensure an arson accelerant usedc. Ex. Fire set by accidental use of a rug cleaner on a carpet.

5. Search for igniters like matchesa. Force of habit could cause one to blow out match and toss

away6. Clothing of suspect may still have accelerants7. Freeze soil and plant samples believed to have accelerant

a. Bacteria can decompose itE. Arson analytical techniques

1. GC is very important instrument2. Typical accelerants are gasoline and kerosene

a. Made of lots of hydrocarbons3. GC separates hydrocarbons to identify specific accelerant

4. “Headspace technique” involves heating airtight container with sample

a. Syringe used to extract vaporized volatile and put into GC5. Vapor concentration technique places charcoal strip in container

a. Container heated so charcoal can absorb accelerant vaporb. Allows for increase amount of accelerantc. Allows for increase in sensitivity for GC testing

F. Explosives1. Mostly face incidents with homemade explosives2. Scientist must search scene for chemical remainders3. Explosion different from fire by rate of creation of gas and heat4. Container that has explosives can become projectile like in a pipe

bomb5. Blast effect is outward rush of gasses which can knock down

objects6. Speed of explosive deterioration varies greatly allowing for

classificationa. Low and high explosivesb. Low explosives speed called speed of deflationc. High explosive called sped of detonation

G. Low explosive1. Rapid oxidation produces, heat, light and subsonic pressure wave2. Slow burning rates make them good for propellants for ammo and

rockets3. Usually are only dangerous if confined4. Most common are black powder and smokeless powder5. Black powder made of K, charcoal and S

a. Used as a safety fuse because it burns slow, allowing time to get away

6. Smokeless powder is a nitrogen based compound7. Creation of low explosive only requires oxidizing agent and fuel

a. Potassium chlorate as agent and sugar as fuel can be dangerous if confined

H. High explosives1. Extremely rapid oxidation accompanied with violent high speed

shockwave that smashes and shatters2. Show variety of sensitivities that allow for further classification

a. Primary explosives are very sensitive to heat, shock or friction

i. Often act as primers because used to detonate other explosives

b. Secondary explosives are insensitive to heat, shock or friction

i. Will burn instead of explode if not confinedii. Ex. TNT

I. Collection and analysis of explosives

1. Most important item is to collect samples at scenea. There is usually some undetonated material

2. Explosives leave a crater at origin of blasta. Soil and material samples from this crater

3. Material just near origin may contain fragments of explosive4. Wire-mesh screens used to sift through remains5. High priority to find detonating device6. EGIS system can be used in the field to detect vapors from

surfaces suspected of containing explosives7. Microscopic examinations of undetonated material and detonating

devicea. Done to locate and help identify explosive

8. After microscopic examination, specimens are rinsed with acetonea. Most explosives have high solubility in acetone

9. Acetone extract then analyzed by color tests, TLC, GC and mass spectrophotometry

10. Infrared spectrophotometry can be used as a confirmatory testJ. Taggant strips can be placed in some explosivesK. Some survive detonation allowing investigators to better trace explosives

XVIII. Forensic serologyA. Serology is the study of antigen-antibody reactionsB. Structure of blood

1. Plasma is mostly water and carries content of blood2. Cells

a. Erythrocytes (RBC) carry oxygen due to hemoglobinb. Leukocytes (WBC) fight off antigensc. Platelets are responsible for clotting

C. Antigens on body cells1. Present to allow one’s body to recognize self2. Responsible for conferring blood type

a. A-B-O blood systemi. A has A antigen on its cellii. B has B antigen on its celliii. AB has bothiv. O has neither

b. Rh blood systemi. Positive blood types have a specific antigen

Called D factorii. Negative do not

D. Antiserum is part of blood that carries an antigen1. Almost every antigen has a specific antibody to destroy it2. Antibodies attach to antigen causing agglutination

E. Blood donating and receivingF. Blood typing is done by adding antibodies for A, B, and D antigens on

blood cells

1. Ex. agglutination of blood when antibody A is added means A antigen is present. Individual is either A or AB

G. Population distribution of blood types1. O is 43%2. A is 42%3. B is 12%4. D is 3%

H. Immunoassay techniques1. Can be used for applications outside blood types2. Can test for certain drugs and toxins by using antibodies3. Antibodies are not found in humans so are synthesizes

a. Usually inject compound with drug one is testing for into animal

b. Animal makes antibodies because it is a foreign substance4. EMIT is enzyme-multiplied immunoassay

a. First add to suspects urine, antibodies to drug testing forb. Drug will then react and combine with antibodyc. Second chemical added to remove any unused antibodiesd. Amount of unused antibodies is measured and correlated

with amount of drug presente. Often used to test or marijuana metabolites in urine

I. Characterization of blood stains1. When blood is found at crime scene must determine:

a. If it is really bloodb. Species of bloodc. How closely it can be associated with a specific individual

2. Phenolphthalein is used to determine presence of blooda. Binds due to peroxidase-like activity of hemoglobinb. When blood, phenolphthalein and peroxide added together,

a deep color will appearc. Process also called to Kastle-Meyer color test

3. Hemastix® is a dipstick for blooda. Stick moistened with distilled water and dipped into sampleb. Presence of blood turns stick green

4. Luminol reagent tests for blood by production of light rather than color

a. Extremely sensitive and can detect minute amounts of blood

b. Does not interfere with subsequent DNA analysis5. Precipitin test determines if blood is human or animal origin

a. Test chemical made by injecting animal with human bloodb. Antiserum containing human antibodies created by animal

are then collectedc. Can inject one species into another to make a wide variety

of animal antiserums

BLOOD SPLATTER ANALYSIS

BACKGROUND:Students have learned about the relationship between direction and rate of movement of a bleeding person and the resultant pattern of blood splatter.

PROCEDURE:Students will have samples of “stage blood” and long sheet of rolled paper. The paper is placed on the floor, and students will move over the paper at various rates and directions while dropping “blood” onto the paper. They will analyze the patterns, and make correlations with the direction and speed of movement.

d. Tests are sensitive and can test for blood as old as 10-15 years

6. DNA analysis used to determine specificity to individualJ. Blood stain patterns

1. Important observations and conclusionsa. Surface texture: harder and less porous material, less

spatter resultsb. Direction the blood traveled can be determined by shape of

staini. Pointed end of stain is direction it was traveling

c. Possible to determine impact angle of blood on a flat surface by measuring degree of circular distortion of stain

i. Blood at right angle striking surface gives rise to circular ii. As angle decreases, stain becomes elongated in shape

d. Origin of blood spatter can be determined in two dimensions

i. Drawing straight lines through multiple stains will produce a point of intersection. The point is the origin

K. Forensic characterization of semen1. Acid phosphatase color test done to determine presence of semen

a. Based on prostate gland secreting acid phosphate2. Use of a microscope at magnification of 400X provides ideal

evidence if spermatozoa are founda. Done by immersing stain on garment into water and then

placing onto slide3. Many people now have vasectomies or low sperm counts

a. Problem solved by presence of p30 protein in semen fluidb. Antibodies to this protein made by injecting in to other

animals

c. Antiserum then added to suspected semen stainL. Collection of rape evidence

1. Bruises and injuries usually indicate a rape2. Forceful contact usually leaves a lot of evidence behind

a. Hairs, semen, fiber, etc…3. All outer garments form both parties should be carefully removed

over a large paper to catch any fallen debris4. Place where rape occurred should be sent to lab or cut out piece if

too big to send to lab5. Victim should be given a physical examination as soon as possible

a. Pubic combingsi. Need 15-30

b. Vaginal swabsi. Allow swab to air dry before packagingii. Place another 2 smears directly on a slide

c. Rectal swabsi. Allow swab to air dry before packagingii. Place another 2 smears directly on a slide

d. Oral swabsi. Allow swab to air dry before packagingii. Place another 2 smears directly on a slide

e. Pulled head hairsi. Need 50 hairs from various scalp regions

f. Blood sampleg. Fingernail scrapingsh. All clothing

6. Suspect examined for:a. All clothingb. Pubic hair combingsc. Pulled head haird. Blood sample

XIX. DNA technologyA. DNA is the genetic material that makes up chromosomesB. Chromosomes contain grouped pieces of DNA called genesC. Each gene codes for the creation of certain phenotypes

1. Creates phenotypes by making proteinsD. DNA structure (Watson-Crick Model)

1. Double stranded a. Strands held by hydrogen bonds

2. Made up of monomers called nucleotidesa. Phosphateb. 5-carbon sugarc. Nitrogenous base

i. Only part that shows variationii. Provides enough variation due to size of molecule

3. G and C pair, T and A pair specifically

E. Protein synthesis1. Triplet code on DNA ultimately codes for specific amino acid2. Transcription creates mRNA3. Translation is actual synthesis of a protein

F. DNA synthesis1. Semiconservative2. Requires helicases to unwind strand3. Single-stranded binding proteins hold strands apart4. RNA primer starts strand synthesis5. DNA polymerase adds nucleotides by adding appropriate bases

a. Uses original strand as a templateG. Recombinant DNA is DNA that contains genes from two different sources

1. Isolate gene from eukaryotic cell2. Place plasmid into a vector (plasmid) then into bacteria where it

replicates3. Used for producing protein or giving organism a new ability4. Restriction enzymes cut DNA in specific places called restriction

sites cut produces sticky endsa. Will form H-bond with complimentary pairb. Cut different genes with same restriction enzyme produces

complimentary sticky endsc. Fuse pieces together with DNA ligased. DNA now called recombinant DNA

5. Induce bacteria to uptake vector by transformationa. CaCl2 or heat shock

6. Place bacteria in nutrient media to reproduceH. Restriction fragment length polymorphisms

1. Based on idea that genome has repeating units that do not code for proteins

a. These are called RFLPsb. Found randomly throughout an individuals genomec. Purpose in genome is not known

2. DNA strand is subjected to restriction enzymesa. Differences in individuals produce different sized

restriction fragmentsb. Interested in fragments that are RFLPs

3. Fragments are separated by gel electrophoresis4. Southern blotting technique used to label just RFLPs in entire

DNA stranda. Labeled with single-stranded DNA pieces that are

radioactive5. Photographic film is laid over DNA

a. Probes will highlight where particular RFLPs are found6. Process can be repeated with different restriction enzymes and

probesa. This will allow many variations to appear

DNA ANALYSIS

BACKGROUND:Students have learned about the methods of collecting, analyzing, and

matching DNA samples.

PROCEDURE:If possible, students will perform electrophoresis on samples in the lab. If

not, students will be provided with samples of DNA “fingerprints”, and will match them with those of several “suspects”.

EXPECTED OUTCOMES:Students will apply their knowledge of DNA analysis to sample DNA

“fingerprints”.

b. Chance of 2 people have same RFLPs is 1/100c. 1/100 X 1/100 X 1/100 X 1/100 = 1 in hundred million

I. Polymerase chain reaction (PCR)1. Allows for DNA to be replicated for analysis2. Heat DNA to break H-bonds so strands will separate3. Add primers, DNA polymerase, nucleotides4. Cool solution which allows nucleotides to combine with original

DNA strandsJ. Short tandem repeats (STR)

1. Loci on chromosomes that have small repeating units of nucleotides

a. Smaller than RFLPs2. Less susceptible to degradation so more readily obtained from

crime scene3. Smaller size also allows for use of PCR to make more DNA4. There are hundreds of types of short tandem repeats5. Procedure

a. PCRb. Electrophoresis

i. Determines number of particular STR testing for c. Repeat procedure with another type of STR

6. Correlate results with percentage of found in population7. Multiplexing means to use several different types of STR to

individualizeK. Sex of individual can be determined from DNA by using amelogenin gene

1. Gene is six bases smaller on X chromosomes2. Electrophoresis will show males with two lines, females one

L. Mitochondrial DNA1. Inherited only through mother2. All maternally related relatives will have same mitochondrial DNA

3. Useful if DNA sample is not obtainable from victim or suspect4. Determine sequences of small pieces of the DNA

a. PCRb. Sanger sequencing method

M. Combined DNA index system1. Database of DNA collected from criminals2. Database will allow all 50 states to match DNA samples with

known samples of past criminals3. Samples of DNA are taken of most criminals in every state

N. Collection and preservation of evidence for DNA analyses1. Safety of collector is important

a. AIDSb. Hepatitis B

2. Where gloves for own protection and to prevent contamination3. All clothing of victim and suspect should be sent to lab, even if one

doesn’t see blood or other body fluids4. Do NOT package biological material into plastic or airtight

containersa. Moisture in these would enhance growth of DNA

destroying bacteria5. Blood on surface that cannot be removed should be removed with

a cotton tipped swab that is moisteneda. After collection allow swab to dry

6. All biological materials should be refrigerated7. Buccal cells can be obtained by rubbing swab on inside of cheeks

a. Cells will provide a DNA sourceO. Can also obtain DNA samples from razors, brushes, toothbrushes, etc…

XX. Fingerprint analysisA. Fingerprints are an individual characteristic

1. Determined by prints ridge characteristics (minutiae) a. Ridge endingsb. Bifurcationsc. Enclosuresd. Ridge crossings

2. Identity, number and relative locations are of these are analyzed3. In court, a point by point comparison must be shown for these

minutiae4. Over 150 individual minutiae on average fingerprint

a. Crime scene may reveal only part of a fingerprintB. Fingerprint will remain unchanged over persons lifetime

1. Skin structurea. Epidermis is outer portion of skinb. Dermis is inner portionc. Dermal papillae separates both

i. Responsible for print patternii. Does not change after formation in fetus

2. Each ridge has a line of single pores used to excrete sweata. Perspiration and oils are spread onto surface of object

touchedb. Leaves a print of the ridges on the fingerc. These are invisible to eye and are called latent fingerprints

3. Attempts to scar are fruitless because would need to scar entire hand

a. Impossible to damage all minutiae on handb. Scarring only provides a greater characteristic in which to

compareC. Fingerprints have general ridge patterns that permit them to be

systematically classified1. All fingerprints divided into three categories, loops, whorls and

arches2. Loops have ridge from one side, recurving and exiting from other

sidea. If loop opens toward little finger called ulnar loopb. If it opens toward thumb called radial loopc. Core is the approximate center of loopd. Pattern area of loop is surrounded by two diverging ridges

called type lines3. Whorls are divided into four distinct

a. Plain whorl and central pocket whorl both have at least one ridge that makes a complete circuit

i. If straight line connect two deltas then plainb. Double loop has two loops in one fingerprintc. Accidental is either unclassified or has combination of

other whorl types4. Arches are divided into two types

a. Plain arches formed by ridges entering one side and exiting on other side

i. Rises to from a wavelike pattern b. Tented has sharp rise

FINGERPRINT CLASSIFICATION

BACKGROUND:

Students have studied the main classification of fingerprints. They are familiar with the characteristic appearances of loops, arches, and whorls.

PROCEDURE:

Students will be provided with a set of 10 fingerprints on a fingerprint card. They will classify each print as a loop, arch, or whorl – and even include subsets of each, at the discretion of the instructor. They will then classify the entire set of prints according to the FBI classification system.

EXPECTED OUTCOMES:

Students will be able to classify any fingerprint as a loop, arch, or whorl.Students will be able to classify an entire set of prints by the FBI system.

FINGERPRINT IDENTIFICATION

BACKGROUND:

Students have learned about the individualization of a single fingerprint. The specifics of minutiae identification and location – including bifurcations, ridge endings, islands, enclosures, ridge crossings, etc., have been covered.

PROCEDURE:

Students will be provided with one fingerprint on paper and a magnifying glass. They will identify and locate at least five particular minutiae on the print. They will also create an enlarged sketch of the print, with minutiae locations indicated.

EXPECTED OUTCOMES:

Students will be able to locate and identify minutiae in fingerprints from sample prints, which have been provided. They will also prepare an enlarged version of the print, and be able to present their results to a group (as would occur in court).

INKING AND ANALYZING A SET OF FINGERPRINTS

BACKGROUND:

This activity follows the previous activities and serves as a summary of these two activities. Students have been instructed (by demonstration) how to properly ink and roll a set of fingerprints on a fingerprint card. They know how to recognize a good quality print.

PROCEDURE:

Students will pair up, and each student will ink and roll the fingerprints of a partner on a fingerprint card. Each student will then classify his/her own set of prints, and select one particular print to locate as many minutiae as possible. Each student will prepare a sample sketch of that one print.

D. Detecting fingerprints1. Three types of prints found at crime scene

a. Visible prints occur if fingers covered in colored materialb. Plastic prints are impressions left on soft materialc. Latent are produced from sweat glands on ridges

i. Invisible to eye2. First problem is to find place where fingerprints are located

a. Reflected ultraviolet imaging systemi. UV light strikes print. Light reflected back differentiating print from backgroundii. Various colored powders adhere to perspiration residue

3. Prints on hard and nonabsorbent materials requires use of superglue® fuming

a. Cyanoacrylate ester in glue binds to printsb. Glue is placed on absorbent cotton and sodium hydroxide is

addedi. Creates fumes which bind to fingerprint

c. Fumes can also be created by heating glued. Fumes and object with print must be in an enclosed area

4. Prints on soft or porous materials requires one or more treatments with chemicals

a. Iodine fumingi. Vaporized iodine combines with sweat residueii. Not permanent and fade when fuming stops

b. Ninhydrin reacts with amino acids found on sweat residuei. Forms a purple-blue colorii. Sprayed with an aerosol can

c. Physical developer

VISUALIZING, LIFTING, AND MOUNTING LATENT FINGERPRINTS

BACKGROUND:

Students have learned about the various means of latent fingerprint visualization, including Superglue ® (Cyanoacrylate ester) fuming and powder dusting.

PROCEDURE:

The Superglue ® fuming method of latent print visualization will be demonstrated by the instructor.

Students will be provided with an object – soda can, beaker, etc. which contains a good quality latent print from the instructor. Students will select the appropriate powder color, and dust the object to visualize the latent print. Each student will then lift the print on fingerprint tape, and mount the print on the appropriate colored backing card.

Optional Extension: Students will match this lifted print from a set of instructor-generated “suspect” prints. Several specific minutiae locations must be indicated to support the student’s match.

i. Silver nitrate based chemicalii. Very good at finding latent fingerprints on porous material that had been previously wetiii. Washes away any proteins so do after ninhydrin test

5. Use of laser light makes latent prints visiblea. Works because some components of sweat fluoresceb. Chemical scan be added to area that makes it fluorescec. Laser light has mostly been replaced with high energy

lightsi. Allows selection of various wavelengths of lightii. Cheaper and can be carried more readily

E. Preservation of developed prints1. First step is take a photograph of print2. Preservation technique depends on size of object3. Small objects are taken as a whole and wrapped in cellophane4. Large objects use the “lifting” technique

a. Use scotch tape to pick up powder on printsb. Tape then adhered to an index card

XXI. Physical evidence of firearmsA. Bullet comparisons

1. Inner striations of gun barrel leave impression so on bulletsa. These striations are individual characteristics

2. Gun barrel manufacture in involves drilling hole into steel barrel

a. Each of several techniques leaves behind:i. Spiral grooves to make bullet rotateii. Lands are found between grooves

b. Whatever technique used by manufacturer will give a class characteristic to that type of gun

i. Each of a specific type of gun will have same number of grooves running in same direction and same number of lands

3. No two gun barrels are samea. Due to imperfections in making or boring of rifleb. Exist as fine lines and striationsc. These from individual characteristics

4. First step in identification is to obtain test bullets by firing from suspects gun

a. Bullets then compared on class characteristicsi. Includes number and type of grooves and landsii. If no match then two different guns

b. Use the comparison microscope is vitali. First need to find matching area on both bulletsii. Then both are rotated in same direction to find other matchesiii. May not find a complete match

Rust and grit may have a small effect Distorted bullets from impact may not

have a large area to compare Slight changes in barrel after many uses

iv. These usually don’t interfere with matchingc. Typical forensic scenario involves a bullet from crime

scenei. Scientist must determine type of gun and manufacturer first

d. Shotgun barrels are smooth and do not have markings5. Cartridge cases

a. Bullets shell is also impressed with markings form contact with weapons firing and loading mechanisms

b. These can be reproduced by firing gunc. Can use to individualize weapon or shotgun

B. Gunpowder residues1. Help resolve firing distance determinations2. When bullet is fired, some of the unvaporized powder is also

expelled3. Determination based on the distribution of powder patterns or the

spread of a shot pattern4. Patterns found by firing suspects weapon at various ranges and

comparing to scene

BALLISTICS – GUNSHOT ANALYSIS IN GLASS

BACKGROUND:Students have learned about the characteristics of gunshot patterns in glass.

PROCEDURE:Students will be provided with a sheet of automotive glass that has several shots through it. By examining cratering and fracture patterns, students will determine the direction and sequence of shots.

EXPECTED OUTCOMES:Students will apply prior learning to this practical lab activity.

5. If weapon not available than can estimate distance by some patterns form impact of bullet

a. If in contact or extremely close than will be a high concentration of smoke like vaporous lead

i. Loose fibers around hole will show burn marks or melting from flame dischargeii. Blowback of muzzle gasses produces star-like tear pattern around hole

b. Halo of vaporous lead shows distance of 12 to 18 inchesi. Scattered specks of unburned or partially burned powder without any soot occurs up to 25 inches

ii. Further the distance, the more spread the specksc. Lack of specks means it was shot further than 3 feet

6. Garments suspected of being shot:a. First examined under microscope to find gunpowderb. Use of chemicals if evidence not scene with microscope

i. Nitrites are type of chemical formed from incomplete combustion of gunpowder

ii. Greiss test is a chemical test to develop patterns of gunpowder residues around bullet holes

Visualize nitrite particles

7. Primer residues on handa. Residue is not only blown forward but back on handb. Residue contain barium and antimonyc. Determination of someone firing a gun is done by

comparing the concentration of these to front and back of hand

d. Difficult because normal washing or rubbing washes residue away

BALLISTICS – GUNSHOT RESIDUE

BACKGROUND:Students have learned about gunshot residue patterns, and how to relate

this to distance between a shooter and the target.

PROCEDURE:Students will be provided with samples of mock gunshot residue

patterns in clothing. They will analyze the patterns to determine the distance and angle between the shooter and the target.

EXPECTED OUTCOMES:Students will increase their skills of observation and measurement.

8. Collection and preservation of firearm evidencea. Do not lift gun because residue will be lostb. If gun must be touched for finding prints, touch at

checkered grip areac. Safety precautions necessitates unloading the gun

i. Great detail must be taken to describe contents and position of gun pieces before unloading

d. Bullet recovery in objects requires caution not to scratch bullet, deleting markings on outside of bullet

i. Dig around bullet to avoid problemii. Place initials of investigator on either end of bullet

XXII. Physical evidence of tool marksA. Usually associated with breaking and entering and burglaryB. Usually caused by indented impressions in softer material or scrapingsC. Examining impressions allows class characteristic of type of weapon usedD. No attempt should be made to place toll back into tool marl to find a

match1. Must make controls by using suspects tool on similar material

a. Difficult because need just right angle, force, etc…E. Chips of paint adhering to tool allows best evidence for forcible entryF. Other impressions include tire, shoe, fabric, etc…

1. All impressions should first be photographeda. Ruler to show size should be includedb. Only needed if original impression damaged

2. Casting can be used when impressions in soft eartha. Use plaster of Paris

XXIII. Document analysisA. Document analysis includes identifying erasures, indented writings and

questioned documentsB. Individual characteristic because no two people write exactly alike

1. Develop subconscious writing habits over time due to repetition

QUESTIONED DOCUMENTS – FORGERY DETECTION

BACKGROUND:Students have learned about various methods of handwriting forgery.

PROCEDURE:Students will work with a partner. They will exchange signature samples,

and attempt to use the various methods discussed in class to forge their partner’s signature. They will also be provided with an actual signature and a forgery of that signature, and they will reveal the forgery through several points of comparison.

EXPECTED OUTCOMES:Students will improve their forgery skills (!), and improve their skills at

detecting forgeries.

QUESTIONED DOCUMENTS – COUNTERFEITING

BACKGROUND:Students have learned about various methods of counterfeiting currency.

PROCEDURE:Students will examine several denominations of currency. They will identify the characteristics of currency that make it identifiable as authentic, and compare it with examples of counterfeit currency.

EXPECTED OUTCOMES:Students will increase their skills of observation and detection.

2. Individual because involves mechanical, physical and mental functions

3. Variations include angularity, slope, speed, pressure, letter and word spacing, relative dimensions of letters, connections, pen movement, writing skill and finger dexterity

4. Also variations in margins, spacing, crowding, insertions and alignment on paper

5. Also spelling, punctuation, phraseology and grammar6. No single characteristic can be used but need series of common

characteristicsC. Writing habits are altered by alcohol and drugsD. Need adequate number of exemplar to compare documents

1. Must use same type of pen and paper as they me cause alteration2. Samples must be within a three year time period3. Sometimes suspect is forced to write a sample

a. Must be several pages longb. Dictated text should have similar words as questioned

documentc. Use same type of pen and paperd. Dictation of text should at least occur three times

QUESTIONED DOCUMENTS - SECRET INKS

BACKGROUND:Students have learned about the chemistry behind various “secret inks”.

PROCEDURE:Students will write notes with several secret inks, and exchange these notes with classmates. The classmates will use appropriate methods to visualize these secret inks.

a. A solution of NaOH ink can be visualized with phenolphthalein.

b. A milk or lemon juice ink can be visualized with slow warming (over a light bulb).

c. A note written with more pressure than usual will make an impression on papers underneath the note. These can be visualized with simple “shading” with a pencil.

EXPECTED OUTCOMES:Students will understand the chemistry behind the visualization of so-

called secret or invisible inks.

E. Alterations and erasures to documents can be distinguished through s microscope

1. Upper parts of paper will be disturbed2. Some inks show infrared luminescence when exposed to infrared

lighta. Can show alteration if different color ink was used to

change document3. Charred documents can be deciphered by shining light against

paper to create a contrast between it and paper

F. Indented writing may be able to be distinguished by side lighting

QUESTIONED DOCUMENTS – TYPEWRITER FONTSBACKGROUND:

Students have learned about the various features of print lettering, and have examined the imperfections of printing associated with particular typewriters.

Note: This activity can be modified for application to computer printers.

PROCEDURE:Students are provided with a sheet of sample fonts from various typewriters. They are then given a mock ransom note, written on one of the typewriters. They are to match the note with the machine from which it was printed, and be prepared to indicate particular points of comparison in a courtroom type setting.

Optional Extension: A note can be printed on an actual machine in the school, and students must print test samples on “suspect” machines before they make a match. Of course, proper planning of this activity is required to ensure that students wishing to test their machine do not constantly interrupt people in the school.

EXPECTED OUTCOMES:Students will improve their skills of observation and comparison.