Quiz #3 (Tread, Fingerprints, Drugs)

Visible 2D Print:

Describe the three types of shoe-prints found at the crime scene (shoe-prints types objectives).

Dirt of other material picked up by shoe or tire and deposited onto flat, hard, surface.

COLLECTION: examination quality photo.

Visible 3D Print:

Describe the three types of shoe-prints found at the crime scene (shoe-prints types objectives).

Shoe-print made of soft material (dirt, snow).

COLLECTION: make a cast of the print.

Latent 2D Print:

Describe the three types of shoe-prints found at the crime scene (shoe-prints types objectives).

Barely visible dry dust/residue print. Wet print or faint impression.

COLLECTION: Processed before photo.

Explain why all shoe-prints should be documented, even if the prints are suspected from coming from the same shoe (documenting objectives).

Could have different impurities/impressions. EX: stepped in/on something, makes print different.

Describe how a barely visible shoe-print is located (documenting objectives).

Main light turned off, low light is used at an angle to try and find footprint.

Describe how a 2d shoe-print can be documented and collected (documenting objectives).

Visible 2d: Examination quality photo.

Latent 2d: fingerprint powder, lifted with adhesive or gelatin, transferred to solid background.

Describe how a shoe-print is collected using electrostatic lift (documenting objectives).

Charge is used to lift light dry materials from surface to back film. The lift provides more contrast and can be photographed for evidence.

See image on slide 21.

Describe how a 3d shoe-print is documented and collected (documenting objectives).

photograph, then use dental stone cast.

in snow: spray with colored wax.

Describe the class characteristics and individuals characteristics of shoes (shoe analysis objectives).

Pattern and size.

Cuts, rocks, wear marks.

Explain how the individual characteristics of shoes can change over time (shoe analysis objectives).

Can become worn or damaged.

Explain why a car with replacement tires may be easier to identify than a car with OE tires (Tire terms objectives).

Replacement tires are typically different from OE tires.

Explain how a treat wear indicator can be used as a class characteristic of tires (Tire terms objectives).

It begins to show after wear.

Wheelbase (Tire terms objectives).

Front center to back center.

Track Width (Tire terms objectives).

right center t left center.

*front and rear tires are not always the same.

Turning Diameter (Tire terms objectives).

Diameter of a circle made when the wheels are fully turned.

Explain how a 2d and 3d tire impression should be documented and collected (documenting objectives).

dental stone casting (full length of tire rotations), photograph, 2d lift.

Describe the class characteristics and individual characteristics of tire impressions (documenting objectives).

Length, size, tread design, wear marks.

Cuts, rocks, wear marks.

Name the raised and lowered areas of a fingerprint (characteristics objectives).

Ridges: hills/raised

Furrows: valleys/lowered

Identify the part of the finger that makes contact with a surface (characteristics objectives).

Ridges

recall identical twins do not have identical fingerprints (characteristics objectives).

Pattern can be affected by genetics.

Identify 3 different patterns of prints (characteristics objectives).

Arch, loop, whorl.

See images on slide 12.

Identify 4 different minutia of prints (characteristics objectives).

Bifurcation, ridge ending, island, dot.

See images on slide 13.

Describe how computer software compares fingerprints (characteristics objectives).

Compares locations of minutia.

Describe the Bertillion system of identifying individuals (History objectives).

Used 11 body measurements to identify an individual.

Describe the Henry system for identifying individuals (History objectives).

Allowed fingerprint records to be searched, based on all 10 prints, so matching one print would be difficult.

A= arch, U= Ulnar loop, R= radial loop, W= whorl.

Name the US fingerprinting database (History objectives).

AFIS- Automated fingerprint identification system.

Describe the limitations with how a database compares fingerprints (History objectives).

Not all fingerprints are submitted into the system, dirt or impurities can affect a finger print.

Google.

Describe the three types of fingerprints (developing fingerprints).

Visible: left by dirt, grease, blood, does not need processing.

Impression: indented in a soft material, may not need processing.

Latent: requires processing to make visible, process depends on type of material.

Describe the five methods for developing fingerprints (developing fingerprints).

Dusting: apply powder

Iodine Fuming: iodine crystal sublimes (solid->gas), the fumes become trapped in print, iodine trapped in lipid components.

Silver Nitrate: Not often used, silver reacts with CI- ions.

Ninhydrin: reacts with amino acids, purple color. painted, sprayed, or dipped. Heated

Super Glue Fuming: fumes in cabinets with heat or base to produce an off-white print.

Identify the type of object or surface on which each method works best.

Identify the correct invisible component in the fingerprint each method develops (developing fingerprints).

Dusting: non-pores items, large items.

Iodine fuming: porous and non- porous, valuable items.

Silver nitrate: porous.

Ninhydrin: porous

Super glue fuming: non- porous

Describe photo, scan, and lift methods (developing fingerprints).

Fingerprints must be photographed or lifted after development.

Photo: Take picture with scale.

Scan:

Lift: Tape placed over dusted print, tape then removed and placed on white card.

Distinguish the difference between the terms controlled substance and drug of abuse (drug schedule objectives).

Controlled: substances controlled by federal or state laws. (possession for personal use is misdemeanor on 1st offense).

Some drugs of abuse are not illegal.

Name the legal act that scheduled drugs (drug schedule objectives).

Controlled Substances Act, 1970. Established legal definitions for drugs, set up 5 schedules for classification of drugs and penalties for each.

Describe the drug classification categories Schedule 1 and Schedule 2 (drug schedule objectives).

1: most severe penalties, high potential for abuse, no accepted medical use.

2: high potential for abuse but have an accepted medical use.

Classify controlled substances as natural or synthetic (drug type objectives).

N: marijuana, cocaine, morphine, codeine, psilocybin/psilocin.

S: Phencyclidine, amphetamines, barbiturates.

SS: prepared chemically from a natural substance- heroin, LSD.

Heroin and Opiates: Describe the legal definition, origin, legal issues, and lab issues for given controlled substances (drug type objectives).

Opium derivatives, their salts, isomers, and salts of isomers.

Poppies originated in hot, dry, Middle east.

Morphine and codeine occur naturally.

Heroine is synthesized from morphine as passes blood-brain barrier.

Opioid pain medication made from morphine: hydrocodone, hydromorphone, oxycodone, oxymorphone.

Amphetamines: Describe the legal definition, origin, legal issues, and lab issues for given controlled substances (drug type objectives).

Synthetic stimulants covers amphetamine, methamphetamine, and other analogs.

Legal precursors are regulated by limiting purchases.

Cocaine: Describe the legal definition, origin, legal issues, and lab issues for given controlled substances (drug type objectives).

Coca leaves and any salt, compound, derivative, or preparation thereof.

Originates in Andes Mountains and is difficult to grow in other locations.

Medical use as local anesthetic and stimulant.

hydrochloride is powder form, crack is base form. Both are coke, but base form can be smoked.

Fair Sentencing act of 2010 passed to reduce sentencing disparity between cocaine and crack.

Marijuana and Cannabinoids: Describe the legal definition, origin, legal issues, and lab issues for given controlled substances (drug type objectives).

All parts of the plant Cannabis sativa.

Originated in Asia, grows Worldwide.

Psychoactive compounds, primarily delta 9 THC.

Schedule 1, states can decriminalize.

Color Test: Classify and describe the four different screening tests for pills and powders (screening tests for drugs).

Small amount of chemical in spot plate, drop of color changing reagent added, color change noted.

Microcrystal Test: Classify and describe the four different screening tests for pills and powders (screening tests for drugs).

Small amount of sample dissolved in solution, test reagent added- contains another chemical that reacts with drug, insoluble crystal formed.

Shape of crystal suggest drug type.

Impurities may cause unusual crystal formation.

Thin Layer Chromatography (TLC): Classify and describe the four different screening tests for pills and powders (screening tests for drugs).

Dot of drug places at bottom of paper or thin silica place, bottom dipped in solvent; solvent diffuses up plate, solvent carries drug up paper, distance depends on drug.

Different solvents result in different distances. Some systems include color change components.

Gas Chromatography: Classify and describe the four different screening tests for pills and powders (screening tests for drugs).

Similar to TLC, different chemicals will move at different rates through a capillary.

The time it takes to pass through the capillary gives an indication of drug type.

Classify and describe the screening process for marijuana (screening tests for drugs).

Macroscopic: leaf and stem structure.

Microscopic: tiny hairs of leaf surface.

Color test/ TLC: Tests for THC.

Classify and describe the screening process for Peyote (screening tests for drugs).

Macroscopic: Look for cotton-like tufts.

Test for Alkaloids: TLC nd Gas chromatography.

Confirming mescaline not necessary.

Classify and describe the screening process for mushrooms (screening tests for drugs).

Macroscopic: identify ones that contain psilocybin.

Screen: color, TLC, and UV spectroscopy.

Requires confirmations.

Describe the different method for preparing drug samples for confirmation tests (confirmation tests for drugs).

Separate from other chemicals in mixture based on microscopic appearance.

dry wash: liquid dissolves adulterants, solid drug left behind.

Dry extraction: liquid dissolves drug, solid adulterants left behind.

Liquid extraction: entire sample dissolves in aqueous liquid, organic liquid mixed with solution and removes adulterants, sample remains in aqueous layer.

IS: Classify and describe the two drug confirmation methods of mass spectrometry and infrared spectroscopy (confirmation tests for drugs).

IS: UV spectroscopy except a range of infrared light wavelengths are passed through a sample.

Some light passes through, some is absorbed. Different drugs= different patterns.

MS: Classify and describe the two drug confirmation methods of mass spectrometry and infrared spectroscopy (confirmation tests for drugs).

MS: Smash molecule into pieces and measure the mass of each piece.

Each drug breaks down uniquely.