Forensic Science – Comprehensive Vocabulary Review

A comprehensive set of vocabulary flashcards covering fundamental terms, principles, techniques, and classifications presented in the forensic-science lecture notes. The list spans crime-scene concepts, evidence types, bloodstain pattern analysis, DNA, fingerprints, impression evidence, firearms, ballistics, tool marks, and glass fracture interpretation.

Forensic Science

The study of spatial and temporal relationships between people, places, and things involved in crimes, used to reconstruct past events.

Historical Science

A science that works with many clues—some irrelevant—to determine past causes (e.g., forensic science, geology, paleontology).

Proxy Data

Indirect evidence or measurements used to infer information about past events when direct evidence is unavailable.

Experimental Science

Science that reduces variables and works with minimal clues to predict future effects.

Forensic Medicine

Medical specialty applying medical knowledge to legal matters, especially determining cause of death or injury.

Forensic Odontology

Application of dental knowledge to legal investigations, often for human identification.

Forensic Anthropology

Application of biological anthropology techniques to identify and analyze human remains in a legal context.

Forensic Toxicology

Analysis of biological samples to detect drugs, poisons, and harmful substances.

Crime Scene (Chisum & Turvey)

Any area where a crime has taken place.

Crime Scene (Shaler)

The place where participants meet in time and space or where the instrument of the crime is prepared or delivered.

Crime-Scene Processing

Recognizing, documenting, collecting, preserving, and transporting physical evidence.

Primary Crime Scene

Location where an offender engaged in the majority of principal offense behavior.

Secondary Crime Scene

Site of victim-offender interaction not containing most principal offense behavior; supports the crime.

Intermediate Crime Scene

Any scene between the primary and disposal site where transfer evidence may occur (e.g., vehicle).

Disposal Site

Scene where a body is found; may or may not be the primary scene.

Tertiary Crime Scene

Location holding physical evidence but no victim-offender interaction (e.g., weapon dump).

Macroscene

What an investigator immediately sees on entering a scene (body, blood pool, etc.).

Microscene

Invisible or latent traces intimately associated with the macroscene, commonly called trace evidence.

Physical Evidence

Tangible objects found at a crime scene that help reconstruct events.

Testimonial Evidence

Spoken statements by witnesses or experts regarding observations or expertise.

Direct Evidence

Evidence collected directly from a person without inference (e.g., eyewitness account).

Circumstantial Evidence

Evidence requiring inference to connect it to a conclusion (e.g., fiber on suspect’s coat).

Corpus Delicti

Physical evidence establishing that a crime has been committed.

Modus Operandi (MO)

Characteristic pattern of criminal behavior linking related crimes.

Linkage

Process of connecting different scenes, suspects, and evidence; also genetic tendency for nearby DNA markers to be inherited together.

Locard’s Exchange Principle

Whenever two objects come into contact, there is a mutual transfer of material.

Transfer Evidence

Evidence resulting from a contact exchange; essentially all forensic evidence.

Primary Transfer

Direct evidence transfer from one person or object to another.

Secondary Transfer

Evidence transferred from an original source to an intermediate object and then to another target.

Tertiary Transfer

Third-level transfer via two intermediaries before reaching the final substrate.

Pattern Recognition

Process of visually identifying and interpreting repetitive forms or designs in evidence.

Pattern Fit

One item fitted into the pattern of another to show common origin (physical match).

Fracture Fit

Reassembling broken objects to prove they were once a single piece (jigsaw fit).

Pattern Transfer

Mark produced when an object transfers its pattern onto another surface; includes impressions and indentations.

Class Characteristics

Shared features placing evidence in a group but not identifying a single source (e.g., shoe size).

Individualization

Process of reducing class membership to one; evidence unique to a single source.

Positive Control

Known material expected to give a positive reaction, proving a test is working correctly.

Negative Control

Known material expected to produce a negative result, showing no contamination or interference.

Linkage Theory

Concept that evidence can link suspect, victim, crime scene, and instruments.

Evidence Dynamics

Events or factors that alter, move, or degrade physical evidence after its creation.

Establishing Photography

Continuous overlapping photos giving an overall scene perspective; no scales required.

Midrange Photography

Images showing evidence in relation to surroundings; often taken with and without scales.

Close-Up Photography

Detailed images of evidence with and without scales to capture fine characteristics.

Photogrammetry

Technique of converting photographs into accurate 3-D measurements or models.

Crime-Scene Sketch

Hand-drawn representation showing layout, evidence positions, measurements, and orientation.

Triangulation Method

Most precise sketch measurement: object located relative to two fixed points.

Baseline Method

Objects measured perpendicularly from a straight line (e.g., wall or tape).

Polar Coordinate Method

Locating objects by distance and angle from a single fixed point; useful outdoors.

Grid Search

Two-direction perpendicular search pattern covering an area twice for thoroughness.

Zone Search

Dividing a scene into sections prioritized by activity; each searched individually.

Spiral Search

Investigator moves in or out around a central point, useful for locating items thrown outward.

Strip Search

Parallel lanes searched in one direction, often for large outdoor areas.

Adhesion (Fluid)

Attractive forces between unlike molecules, influencing how blood sticks to a surface.

Cohesion (Fluid)

Attractive forces between like molecules; causes blood drops to maintain shape.

Surface Tension

Phenomenon causing liquid surfaces to contract, leading blood droplets toward a spherical form.

Passive Bloodstain

Pattern formed solely under gravity without additional force (e.g., drip).

Transfer Pattern

Blood pattern created when a wet, bloody surface contacts another surface.

Swipe Pattern

Transfer of blood showing motion between a blood-bearing surface and a target.

Flow Pattern

Movement of blood on a surface influenced by gravity or target movement.

Drip Stain

Single blood drop created solely by gravity.

Drip Pattern

Pattern from liquid dripping into another liquid, at least one being blood.

Drip Trail

Series of drip stains indicating movement of a blood source between two points.

Satellite Spatter

Small secondary stains radiating around a parent stain on impact.

Impact Spatter

Blood dispersed through the air by an external force striking a liquid blood source.

Back Spatter

Blood traveling opposite the direction of the force; often associated with gunshot entrance wounds.

Forward Spatter

Blood traveling in the same direction as the applied force (e.g., exit gunshot).

Cast-Off Pattern

Blood released from a moving object (e.g., swinging weapon).

Expirated Pattern

Blood forced out of nose, mouth, or wound via airflow, often containing air bubbles.

Void

Absence of bloodstains in a continuous pattern, indicating an intervening object.

Wipe

Altered bloodstain produced when an object moves through an existing wet stain.

Angle of Impact

Acute angle between blood-drop trajectory and surface it strikes; used to determine direction.

Area of Convergence

2-D point on a surface where trajectories of several drops intersect.

Area of Origin

3-D location in space from which blood originated, established via trigonometry or string methods.

Kastle-Meyer Test

Phenolphthalein presumptive test for blood based on hemoglobin peroxidase activity turning pink.

Luminol

Chemiluminescent reagent reacting with iron in hemoglobin to reveal latent blood with blue glow.

Leuco Crystal Violet (LCV)

Reagent that turns violet in presence of blood; useful for pattern enhancement.

Amido Black

Protein stain dyeing blood dark blue-black to enhance impressions on porous and non-porous surfaces.

Physical Developer

Silver-based reagent developing latent prints and impressions on porous items, especially paper.

FTA Card

Treated paper card impregnated with chemicals that lyse cells and preserve DNA at room temperature.

Buccal Swab

Reference DNA sample collected by rubbing a sterile swab inside the cheek.

Polymerase Chain Reaction (PCR)

Technique that amplifies specific DNA segments for profiling.

Short Tandem Repeat (STR)

Highly variable DNA loci used for human identification.

AFIS

Automated Fingerprint Identification System; database searching friction ridges for matches.

ACE-V

Fingerprint comparison process: Analysis, Comparison, Evaluation, Verification.

Loop (Fingerprint)

Pattern with one delta and ridges entering and exiting the same side; radial or ulnar.

Whorl (Fingerprint)

Pattern with two or more deltas and a recurve in front of each.

Arch (Fingerprint)

Pattern with ridges flowing from one side to the other without recurving; plain or tented.

Minutiae

Level-2 ridge characteristics (bifurcations, ridge endings) used for fingerprint identification.

Cyanoacrylate Fuming

Super-glue vapor polymerizing on latent prints, creating white ridges on non-porous surfaces.

Ninhydrin

Chemical developing fingerprints on porous surfaces by reacting with amino acids to form purple Ruhemann’s purple.

Electrostatic Dust Print Lifter

Device using static charge to transfer dust impressions onto metallic-backed film.

Gel Lifter

Sticky gelatin sheet lifting dust, wet, or blood impressions from varied surfaces.

Bore

Interior diameter of a rifled barrel measured from land to land.

Caliber

Nominal measurement of bore diameter (inches or millimeters).

Full Metal Jacket (FMJ)

Bullet with lead core completely enclosed by a harder metal jacket.

Hollow Point

Bullet designed with a cavity in the nose to expand on impact.

Cartridge

Complete unit of ammunition: case, primer, propellant, and projectile.

Firing Pin Impression

Compression mark on primer from firing pin strike, yielding class and individual characteristics.

Serial Number Restoration

Chemical or magnetic techniques used to recover obliterated identification numbers on firearms.

Interior Ballistics

Study of events inside a firearm from ignition to projectile exit.