chap 9 forensics

Firearms Identification: Discipline determining if a bullet or cartridge was fired by a particular weapon.

Ballistics: Study of a projectile in motion.

Single-shot Pistols: Firearms that fire only one round at a time.

Revolvers: Handguns featuring several firing chambers within a revolving cylinder.

Semi-automatic Pistols: Handguns featuring a removable magazine, firing one shot per trigger pull.

Shotguns: Long guns with a smooth barrel, firing shells containing numerous ball-shaped projectiles called slugs.

Rifles: Long guns with barrels featuring lands and grooves, impressing bullets with these markings during firing.

Gauge: Measurement of shotgun barrel diameter; higher gauge numbers indicate smaller diameter.

Lands: The surfaces between grooves inside a gun barrel.

Grooves: Spiral indentations in a barrel guiding bullets and imparting spin.

Rifling: The process of impressing spiral grooves into a gun barrel.

Striations: Fine lines in the barrel's interior that create individual characteristics on a bullet.

Caliber: Diameter of a gun barrel measured between opposite lands.

Individualization (Firearms): Process of matching striation markings to determine if a bullet traveled through a specific barrel.

Firing Pin: Component of a firearm striking the primer to ignite gunpowder.

Breechface: Surface of the firearm against which the cartridge case is pushed during firing.

Distance Determination: Estimation of the distance between firearm muzzle and target based on residue patterns.

Bullet Wipe: Dark ring around a bullet hole resulting from a weapon fired more than 3 feet away.

Gunpowder Residue: Deposits of unburned or partially burned gunpowder expelled from a firearm.

Primer Residue: Traces of lead, barium, and antimony deposited on the shooter's hand upon firing a weapon.

Greiss Test: Chemical test used to detect invisible gunpowder residues.

Serial Number Restoration: Technique of restoring obliterated serial numbers through chemical etching.

Tool Marks: Impressions or abrasions caused by tools making contact with other objects, characterized by class and individual imperfections.

Comparison Microscope: Instrument used for comparing tool marks or bullet striations.

Casting (Impressions): Method of preserving impressions, such as shoe or tire marks, by creating a physical cast.

Chemical Enhancement: Method to visualize faint or invisible bloody impressions.

Firearm Safety Rule 1: Always keep the firearm pointed in a safe direction.

Firearm Safety Rule 2: Treat all firearms as if they were loaded.

Firearm Safety Rule 3: Keep your trigger finger outside the guard until ready to fire.

Firearm Safety Rule 4: Be certain of your target and what lies beyond it.

Firearm Safety Rule 5: Wear appropriate eye and ear protection when using firearms.