1. Bullet Trajectory
Notes on page 84-85

2. Parts of the Gun Click to add text Firing Pin Rifled barrel Hammer
Magazine
Trigger
Hammer
Firing Pin
Rifled barrel

3. Anatomy of a Bullet
Flash Hole

4. How is a Bullet Fired? Pull the trigger Hammer is pulled back
Hammer is pushed forward
Hits the firing pin which hits the primer
Causes primer powder to spark
Spark goes through flash hole and ignites rest of gunpowder

5. Individual or Class?
There are class characteristics, but when you look at striations, bullets are individual evidence
Cartridge casings are individual because of the extractor and ejector marks

6. Individual!

7. What happens to evidence?
Bullets
Shot forward with a given force
Stop when sufficient force is acted upon it (hits something that slows it down, gravity pulls it down)
Cartridge cases
Ejected from semiautomatic guns (usually to the right)
Remain in cylinder in revolvers

8. Important Forces Forward force of the bullet Downward force of gravity
To some extent:
Wind speed

9. Bullet Trajectory
Trajectory: path of the propelled bullet

10. Determining Location of Shooter
Need 2 reference points to make a straight line
Bullet holes in an object such as a wall, window or furniture
Bullet holes in a victim (entrance and exit count as two!)
Straight line tells investigators that shooter was somewhere on that line

11. Trajectory