Criminology & Crime Analysis Midterm Study Guide

Ch 1-5, 8-12 & 14 Key Terms ONLY

Odontology

The scientific study of teeth

Control Sample

Reference materials used in forensic testing to verify that test results come from ACTUAL evidence rather than the environment it was found in.

Substrate Sample

Unstained or uncontaminated piece of underlying surface material gathered near physical or biological evidence.

Anthropology

Scientific and holistic study of human beings

Daubert Standard

Legal rule used by trial judges to decide if an expert witness can share their scientific or technical opinions in court.

Frye Standard

Legal test used in SOME U.S. courts to decide if scientific evidence and expert testimony are admissible in court.

Michigan v. Tyler

Officials need a warrant, consent, or exigent circumstances to re-enter a burned building after a fire is extinguished to search for arson evidence.

Mincey v. Arizona

4th Amendment does not create a general “murder scene exception” that allows police to conduct a warrantless search of a home just because a homicide took place there.

Admissibility of Polygraphs

Generally considered not admissible in most U.S. federal and state courts.

Class characteristics

Properties of evidence that can be associated only with a group and never with a single source (caliber, lands and grooves, impressions, etc…)

Individual characteristics

Properties of evidence that can be attributed to a common source with an extremely high degree of certainty. (fingerprints, irregular edges on broken objects, etc…)

Formula for determining angle of blood spatter

Angle = arcsin(width/length)

Blow back

Vacuum effect inside a firearm barrel that pulls microscopic trace evidence (like blood, tissue, or fibers) back into the muzzle when a weapon is discharged.

Drawback

Victims blood back-spatters into the interior of a firearm or onto the shooter in close range.

Arterial Spray

High pressure blood pattern that happens when a damaged artery expels blood in pulses that match the heartbeat.

Typology

Classifications of crimes and criminals into distinct categories based on shared characteristics, behaviors, motives, or legal definitions.

PDQ

Paint Data Query

International database that contains chemical compositions of automotive paints.

Area of Origin

Three-dimensional location in the space where blood spatter originally started.

Viewing

Examination of a dead body to determine the cause, mode, and manner of death.

Petechiae

Tiny, pin-point spots that result from the rupture of blood from small capillaries.

Stippling

Pattern of tiny, superficial skin abrasions caused by unburned or partially burned gunpowder particles that strike the skin at a high velocity during a close-range firearm discharge.

Digestion Times

Small meal (1-2 hours) Medium meal (3-4 hours) Big meal (4-6 hours)

Postmortem Interval (PMI)

Estimated time that has elapsed between a person’s death and the discovery of their body / subsequent autopsy.

Glaister Equation

Formula used to estimate the PMI based on the core body temp. EX: hours since death = (body temp) / (cooling rate)

Forensic Anthropology

Post-mortem surgical examination that determines the cause and manner of death.

Pallor Mortis

Post-mortem surgical examination that determines the cause and manner of death (15-25 minutes).

Vitreous Humor

Clear, gel-like fluid filling the eye’s main chamber. Protected from decomposition and bacterial contamination.

Objective lens

The precision optical component closest to the physical evidence in a microscope that gathers light and forms.

Eyepiece lens

The topmost optical component in a microscope or magnifying instrument that you look through to further magnify a real image produced by the objective lens.

Transmitted illumination

Microscope lighting method where the light source is located BELOW the stage, directing light upward.

Vertical illumination

Microscope lighting method where the light source is directed ABOVE the specimen, reflecting off its surface and back up into the objective lens.

Forensic Palynology

Study of spores & pollen

Caliber

Measurement of the firearm’s bullet (rifles)

Gauge

Measurement of the internal diameter of a firearm barrel (shotgun)

Filaments

Trace evidence that leaves textile fiber

Choke

The interior, tapered constriction of a shotgun barrel at the muzzle end.

Birefringence

Single light wave splits into two seperate rays.

Pigment

Insoluble, finely divided coloring substance used as trace evidence to link suspects, weapons, and crime scenes.

Pyrolysis

Thermal chemical decomposition of organic materials at elevated temps in the absence of oxygen.

Measurements of Impurity

Quantify unwanted substances within a primary material.

Float Glass

Critical physical evidence left behind that are transferred during crimes like burglaries, vandalism, and vehicle accidents.

Density

Measure of mass packed into a specific amount of space or volume.

States of Matter

Solid, Liquid, Gas

Sublimation

Solid turns directly into gas without melting into liquid first.

Follicular Tag

Small piece of translucent tissue attached to the root of hair follicle that has been forcibly removed.

Refractive Index

Number that measures how much material slows down and bends light.

Anagen Stage

The active growth phase of the hair cycle where cells divide rapidly in the root and the hair shaft lengthens.

Physiological Dependence

Physical dependence to drugs that results in withdrawal symptoms.

Psychological Dependence

Mental dependence to drug that results in withdrawal symptoms.

Narcotics

Controlled substances that blunt senses, reduce pain, and induce sleep. (Cocaine, heroin, morphine)

Hallucinogens

Psychoactive substances that alter a person’s awareness of their surroundings, thoughts, moods, and perceptions (LSD, PCP)

Microcrystalline tests

Identify specific substances by looking under a microscope and seeing the unique shapes formed when a reagent (chemical) is added.

Schedule I drugs

Substances with a HIGH potential for abuse, no accepted medical use, and a lack of accepted safety under medical supervision. (LSD, Heroin, Ecstasy)

Marijuana and Medical Usage

Illegal under U.S. Federal Law. Often used to treat chronic pain & sleep.

Depressants

Drugs that lower neurotransmission levels and decrease stimulation in the central nervous systems. (Alcohol, Benzos, Opioids)

Synthetics

Man-made chemical substances created in labs to mimic illegal natural drugs (Synthetic Cannabinoids, Fentanyl, Ecstasy/Molly, Acid)

Schedule III Drugs

Medical substances that have lower potential for abuse than schedule I or II drugs. Accepted for medical use (Ketamine, Anabolic steroids, low dose codeine)