Forensic Science CJ110 Quiz #4 (Tread, Fingerprints, Drugs, Toxicology)

What are the tree types of shoe prints found at a crime scene?

Visible 2D, Visible 3D, Latent 2D

What is a Visible 2D Print?

dirt or other material picked up by shoe and deposited onto a flat surface

Which is an example of a Visible 2D print?

What is a Visible 3D print?

sheoeprint made in soft material (dirt or snow)

Which is an example of a Visible 3D Print?

What is a Latent 2D print?

barely visible dust/residue print; wet print or faint impression

Why should all shoe prints be documented even if the prints are suspected from coming from the same shoe?

To prevent destruction of evidence and to maintain integrity of the evidence

How is a barely visible sheoeprint located?

can be visualized by darkening a room and using a bright light at a low angle

How should a Visible 2D sheoeprint be documented and collected?

Taking an examination quality photo

How is a sheoeprint collected using electrostatic lift?

a charge is used to lift light dry materials from surface top lack film; provides more contrast and can be photographed

How is a 3D shoeprint documented and collected?

a dental stone cast picks up detail; photograph impression before casting

How is a Latent 2D print collected and documented?

dusting with a powder can visualize print; lift with adhesive or gelatin and transfer to a solid background

How is a 3D shoeprint documented and collected in snow?

spraying with colored wax highlights print for photo and prevents snow from melting during casting

What are the class characteristics of shoes?

pattern & size

What are the individual characteristics of shoes?

cuts, rocks, wear marks that are unique to one specific shoe

How can the individual characteristics of shoes change over time?

a show may become more worn or damaged, but they do not repair themselves

Why does a car with replacement tires be easier to identify than a car with OE tires?

thousands of cars have the same brand and size of tires, so replacement tires are usually different from original equipment tires

How can a tread indicator be used as a class characteristic of tires?

it shows the after wear; a raised bar under the tire pattern

What is the wheelbase?

from the front center to the back center of the tires

What is the track width?

the width of the right center to the left center; track width of front tires and rear tires are not always the same

What is the turning diameter?

diameter of a circle made when the wheels are fully turned

How should a 2D tire impression be documented and collected?

photos and log of location; entire track should be photographed with overlapping photos with a ruler

How should a 3D tire impressions documented and collected?

long sections (3 feet) should be casted using dental stone

What are the class characteristics of tire impressions?

size, tread design, some wear marks

What are the individual characteristics of tire impressions?

cuts, rocks, wear marks that are unique to one specific tire; can change over time

What are the raised areas of a fingerprint?

Ridges (Hills) ; black

What are the lowered areas of a fingerprint?

Furrows (Valleys) ; white

What part of the finger makes contact with a surface?

Ridges make contact

Do identical twins have identical fingerprints?

No

What are the three different patterns of prints?

arch, loop, whorl

Which is an arch print?

What is a loop print?

What is a whorl print?

What are the four different minutia of prints?

bifurcation, ridge ending, island, dot

What is a bifurcation?

What is a ridge ending?

What is an island?

What is a dot?

How does computer software compare fingerprints?

it compares the locations of the minutia

What is the Bertillon system of identifying individuals?

used 11 body measurements to identify an individual

What is the Henry system for identifying individuals?

using a print card that identifies all 10 prints at once

What is the US fingerprint database?

AFIS (Automated Fingerprint Identification System)

What are the limitations to how a database compares fingerprints?

there must be a known print in the database that can be compared to the unknown sample; with nothing to compare the database can’t compare

What are the three types of fingerprints?

Visible, Impression, Latent

What is a visible fingerprint?

left by dirt, grease, blood, etc; does not need processing

What is an Impression fingerprint?

indented in soft material (butter, putty, etc.); may not need processing

What is a Latent fingerprint?

requires processing to make visible; process depends on type of material

What are the five methods for developing fingerprints?

\-Dusting

\-Iodine Fuming

\-Silver Nitrate

\-Ninhydrin

\-Super Glue Fuming

How do you dust a fingerprint?

\-apply powder to latent print or area

\-adheres to oils in print

\-good for **non-porou**s/large items

What is Iodine Fuming?

\-Iodine crystals are heated to form a gas

\-becomes trapped in the lipid components of the print

\-turns a brown color

\-good for **porous & non-porous**; print fades; good for valuable

What is Silver Nitrate?

\-Silver reacts with Cl- ions in print

\-good for **porous** materials

\-messy, not sensitive

What is Ninhydrin?

\-reacts with amino acids; purple color

\-used on **porous** materials

\-painted, sprayed, dipped; heated

What is Super Glue Fuming?

\-heated to produce an off white print

\-reaction somewhat unknown

\- **non-porous** material

What methods can be shown when fluoresced?

Ninhydrin and Super Glue Fuming prints

What is a controlled substance?

a legal term referring specifically to substances controlled by federal or state lawsControlled Substances Act of 1970

What is the legal act that scheduled drugs?

Controlled Substances Act of 1970 (established legal definitions for drugs)

What is Schedule 1?

drugs carry the most severe penalties; considered to have a “high potential for abuse” and have “no accepted medical use”

What is Schedule 2?

drugs have a high potential for abuse but have an accepted medical use

What is Schedule 3 & 4?

have an accepted medical use and decrease in potential for abuse

What are natural controlled substances?

Marijuana, cocaine, morphine, codeine, psilocybin/psilocin

What are synthetic controlled substances?

Phencyclidine (PCP), Amphetamines, Barbiturates

What are semisynthetic controlled substances?

Heroin, LSD

What are Opiates?

\-opium derivatives, their salts, isomers, and salts of isomers

\-poppies originated in hot, dry Middle East

What is Heroin?

synthesized from morphine as passes blood-brain barrier

What are Amphetamines?

-synthetic stimulant covers amphetamine

\-legal precursors are regulated by limiting purchases

What is Cocaine?

\-coca leaves and any salt, compound, derivative, etc.

\-originates in the Andes Mountains

\-medically used as a local anesthetic and stimulant

What is the difference in cocaine?

Cocaine hydrochloride is powder form; Crack cocaine is base (can be smoked)

What is Marijuana?

\-originated in Asia, but now grows worldwide

\-remains Schedule 1, but states can decriminalize

What are cannabinoids?

\-psychoactive compounds primarily (delta 9-THC)

\-synthetic cannabinoids (spice) are synthetic and interact with cannabinoid receptors

What are Cathinones?

derived from Khat leaves

What is a Kratom?

herbal extract of Mitragyna speciosa

What are Barbiturates?

Scheduled 2-4 depressants

What is LSD & Ecstasy?

a Schedule 1 hallucinogen

What is Psilocybin?

a Schedule 1 hallucinogen from mushrooms

What are the four different screening tests for pills and powders?

\-Color Test

\-Microcrystal Test

\-Thin Layer Chromatography (TLC)

\-Gas Chromatography

What is a Color Test?

\-small amount of chemical in spot plate;

\-color changing reagent added

\-color change noted

What is a Microcrystal Test?

\-small amount of sample dissolved in solution

\-reagent added contains another chemical that reacts w/ drug

\-crystal formed; crystal suggests type of drug

What is a Thin Layer Chromatography (TLC) test?

\-dot of drug placed at bottom of paper or thin silica place

\-dipped in solvent; different solvents result in different distances/some include color change componenets

What is a Gas Chromatography test?

\-similar to TLC; different chemicals will moved at different rates through a capillary

\-the time it takes to pass through gives an indication of what drug it is

What is the screening processes for Marijuana?

Microscopic & Macroscopic Exams

What does a Macroscopic Exam for marijuana identify?

Leaf and stem structure

What does a Microscopic Exam for marijuana identify?

Tiny hairs on leaf surface

What is alternate method to identify Marijuana (Resin ID)?

Color test & TLC (tests for chemical THC)

What is the screening process for Peyote?

Macroscopic Exam & Test for alkaloids, confirming mescaline is not necessary

What does a Macroscopic Exam for peyote identify?

looks for cotton-like tufts

What does the test for alkaloids for peyote use?

TLC & Gas chromatography

What is the screening process for mushrooms?

Macroscopic Exam, a screening, requires confirmation

What does a Macroscopic Exam for mushrooms identify?

identifies that mushrooms contain psilocybin

What does a screening for mushrooms consist of?

color test, TLC, and UV spectroscopy

What are the different methods for preparing drug samples for confirmation tests?

1) Physical Separation

2) Dry Wash

3) Dry Extraction

4) Liquid/Liquid Extraction

What is Physical Separation?

particles are operated based on microscope appearance

What is Dry Wash?

liquid dissolves adulterants; solid drug left behind

What is Dry Extraction?

liquid dissolves drug; solid adulterants left behind

What is Liquid/Liquid Extraction?

\-entire sample dissolved in aqueous (water) liquid

\-organic liquid (oil-like) mixed with solution

\-organic liquid removes adulterants

\-sample remains in aqueous layer

What are the two drug confirmation methods?

Mass Spectroscopy & Infrared Spectroscopy

What is Mass Spectroscopy?

will smash a molecule into pieces and measure the mass of the pieces; every drug will break in a unique way

What is Infrared Spectroscopy?

\-a range of infrared light wavelengths are passed through a sample

\-some light passes through; some is absorbed

\-different drugs have different patterns

What is toxicology?

the study of poisons

What is forensic toxicology?

all aspects of toxicity that have legal implications

What are the three categories of forensic toxicology?

\-Postmortem Drug Testing

\-Workplace Drug Testing

\-Criminal Drug Testing