Ballistics and Firearm Evidence Analysis for Forensics and Crime Scene Investigation Save Groups

least it aint 157 terms

Revolver

A firearm with a rotation cylinder that holds multiple rounds (typically 5-6 cartridges).

Rifling

Spiral impressions inside the barrels of handguns and rifles.

Trajectory

The bullet's flight path once it leaves the muzzle of the firearm.

Ballistics examiner

Someone who is trained and certified to examine and compare ballistic evidence related to the flight of a projectile.

Striations

Cuts made by the rifling, which are scratch marks left on the projectile by the rifling lines of the inside of the barrel.

Newton's 3rd Law

For every action there is an equal and opposite reaction (why a gun recoils).

Long gun

Rifles and shotguns that require 2 hands.

Shell casing

The metal container that holds the other components of a cartridge together.

National Integrated Ballistic Information Network

An automated and shared database where all firearm evidence is submitted by local, state, and federal law enforcement.

Projectile

Any object propelled through the air by force.

Firing pin

A small metal rod inside the firearm that strikes the primer of a cartridge when the trigger is pulled.

Gun Control Act (1968)

All American firearm manufacturers are required to have a serial number stamped on a firearm.

Ballistics

The study of bullets and firearms.

Breech block

The part of the firearm at the rear of the barrel that seals the chamber during firing.

Caliber

The measure of the diameter of the bullet.

Firearm

A weapon capable of firing a projectile using a confined explosive.

Gunshot residue

Traces of smoke and particles of unburned powder carried from the firearm by the expansion of gases.

Barrel

The metal tube through which a projectile travels when a firearm is discharged.

Bullet

The metal projectile fired from a firearm.

Cartridge

A complete single unit of ammunition consisting of four components: the cartridge case, primer, gunpowder, and bullet.

Fully automatic

A firearm that can fire repeatedly as long as the trigger is being pressed.

Lands and grooves

Lands are the raised portions of the rifling, and grooves are the recessed portions.

Handgun

Pistols and revolvers that can fire with one hand.

Facilitate

To help bring (something) about.

Adaptability

The quality or state of being adaptable.

Empathetic

Involving, characterized by, or based on empathy.

Synthesized

To combine or produce; the composition or combination of parts or elements so as to form a whole.

Leverage

Influence or power used to achieve a desired result.

Ballistic examiner vs. firearm examiner

A ballistic examiner examines ballistic evidence; a firearm examiner analyzes physical firearm evidence.

Ballistic evidence

Includes cartridge casings, spent bullets, bullet fragments, firearms, GSR, and wounds caused by discharge.

Caliber of Bullets and Cartridges

Bullets are classified by caliber and length, with common calibers including .22, .357, .38, and .45.

How a Firearm Works

The trigger is pulled, igniting the powder inside the bullet, pushing it into the barrel.

Firearm Identification

A method used to determine if a bullet or cartridge was shot from a particular weapon.

Bullet Markings

Clues from the surface of a bullet, including rifling and striations.

Breech Markings

Marks left on spent cartridge casings.

Firing Pin Markings

Unique stamping left on the cartridge's primer/rim by the firing pin.

Gunshot Residue (GSR)

Traces of smoke and particles of unburned powder carried from the firearm.

Serial Numbers

Identification numbers required on firearms since the 1968 Gun Control Act.

Bullet Trajectory

Path of a bullet that can help locate a shooter.

Ballistics Database

A digital database of firearm evidence submitted by law enforcement.

Collection of Firearms Evidence

Procedures to prevent contamination and damage to evidence.

Class Characteristics

General traits of bullets and casings like brand, weight, and caliber.

Individual Characteristics

Unique marks on bullets and casings such as firing pin and breech face marks.

Integrated Ballistics Identification System (IBIS)

Database that stores images of ammunition's unique markings for comparison.

Bullet Wipe

Residue that wipes off on the first object a bullet enters.

Bullet Yaw

Tumbling of a bullet sideways after passing through material.

Single Bullet Theory

Theory suggesting one bullet caused multiple wounds to JFK and Connally.

Warren Commission Conclusion

Determined that the shot came from behind the Texas School Book Depository.

Autopsy Issues

Problems with the autopsy that led to an incomplete forensic investigation.

Investigative Response

Warren Commission's goal to determine if the assassination was a conspiracy.

JFK Assassination Date

November 22, 1963.

Location of JFK Assassination

Dealey Plaza, Dallas, TX.

Rifle Type Used

Carcano, a military rifle rarely used in homicides.

Ammunition Description

Full metal jacket, cylindrical design for stability.

Condition After Impact

Ammunition remains pristine despite passing through materials.

Timeline Problem

Discrepancy in timing suggests two gunmen.

Fracture Pattern Evidence

Confirms back-of-head entry in JFK's assassination.

Head Movement Analysis

Backward movement caused by muscle stimulation, not shot direction.

Governor Connally's Injury

Injured wrist with elliptical wounds indicating bullet yaw.

Missing Evidence in Autopsy

X-rays and clothing with exit hole were not available.

Lee Harvey Oswald

Ex-marine accused of assassinating JFK, killed before trial.