1. The study of bullets and firearms
Ballistics
The study of bullets and firearms

2. Firearm
A weapon, such as a gun, capable of firing a projectile using a confined explosive

3. Types of Firearms Long guns Handguns Rifles: fire bullets
Shotguns: fire small round pellets (shots) or slugs
Handguns
Revolvers: hold 6 cartridges
Semiautomatic: load up to 10 cartridges in a magazine clip

4. Bullets

5. Cartridge = bullet + case + gunpowder + primer
Caliber = measure of diameter of cartridge
.45-caliber = 45/100 of an inch

6. Bullet Basics Materials: Lead Copper Brass Bronze Steel Aluminum
Jacketed Bullets (travel faster):
Non-jacketed Bullets:

7. Rifling Grooves cut or formed in a spiral down the barrel of a firearm
Increases accuracy and range
Rifling consists of grooves cut or formed in a spiral nature, lengthwise down the barrel of a firearm.

8. Types of marks Rifling pattern Breech mark Firing pin impressions
Extractor mark
Ejector marks

9. Firearms Evidence Firearm Fired bullets Spent cartridge cases
Spent shot shells
Shot
Shot shell wadding
Live ammunition
Gunshot residue (GSR)
Clothing

10. Firearms Examiners will:
Test firearms
Test for gunshot residue to determine distance from muzzle to target
Determine caliber and manufacturer of ammunition components
Match bullets or cartridge casings to firearms

11. Bullet Identification
Obtain standard from firearm
Compare crime scene bullet to standard using comparison macroscope
Unique marks made by imperfections or irregularities = individual evidence

12. Firearms Database
NIBIN: National Integrated Ballistics Information Network
Database of images
Ballistics markings of firearms used in previous crimes
Cartridge casings

13. Bullet Trajectory Wind shield Distance along path of
bullet to window, 23.9”
Path of bullet x y
60 feet
Horizon
Distance along horizon to window, 23.5”

14. Bullet Wounds Generally, entrance wounds and smaller than exit wounds
Entrance: skin stretches when bullet enters body
Exit: bullet carries body tissue and bone with it
Other signs: fibers in wound, GSR, stippling (burnt skin)
Pass through: larger bullets, high-speed bullets

15. Gunshot Wounds