Firearms, Tool Marks, and Other Impressions

These flashcards cover key concepts related to firearms, tool marks, and forensic techniques used in criminal investigations.

Firearms

Devices designed to expel projectiles, classified primarily as handguns and long guns.

Handguns

Firearms designed to be held and fired with one hand, including single-shot pistols and revolvers.

Revolvers

A type of handgun featuring a rotating cylinder that holds multiple cartridges.

Semi-automatic pistols

Handguns that use the energy from firing a shot to load the next round into the chamber.

Shotguns

Long guns with smooth barrels, using ball-shaped projectiles called shot.

Rifles

Firearms with a barrel impressed with lands and grooves to stabilize the bullet during flight.

Rifling

The spiral grooves impressed on the inner surface of a gun barrel, aiding bullet stability.

Striations

Fine lines found in the interior of a barrel, unique to the specific firearm.

Gunshot Residue (GSR)

Particles expelled when a firearm is discharged, often examined for forensic evidence.

Serial Number Restoration

Process of restoring an obliterated serial number through scientific methods.

Tool Mark

An impression or abrasion caused by a tool coming into contact with another object.

Class Characteristics

Attributes shared by a group of tools, such as size and shape.

Individual Characteristics

Unique markings or patterns on tools, which are further modified by wear and tear.

Comparison Microscope

A device used to compare tool marks from a crime scene with test impressions.

Obliteration

The process of removing a serial number, often to prevent identification of stolen property.

Acid Etching

A method used to reveal obliterated serial numbers by applying acid to the surface.

Distance Determination

The forensic analysis of gunshot residue patterns to ascertain the distance of a shot fired.

Test Impressions

Impressions made with a suspect tool, used for comparison against marks found at a crime scene.

Photographing Impressions

Documenting impressions at a crime scene, ensuring to include a scale for measurement.