week 5: ballistics Flashcards
(17 cards)
what are the 3 types of firearms?
- handguns
- rifle
- shotgun
whats is the composition of the basic anatomy of bullets
- primer
- propellant
3.cartridge case - projectiles
what does the propellant do?
pushes the bullet forward
name 3 firearm databases
- national ballistics intelligence service
2.integrated ballistic intelligence service - national firearms licensing management system
what are the 3 types of ballistics?
- interior
- external
- terminal
what is interior ballistics?
the reaction from when the hammer strikes the primer to time in rifling
what is external ballistics?
when bullet leaves the gun, but before it strikes the target
what is terminal ballistics?
studies concerned with target interaction e.g ricochet, smudging etc
what is smudging + what does it indicate?
where smoke and soot is deposited around the wound
- indicates the gun was held close to the victim, but was not in contact
what is searing + what does it indicate?
a singeing effect due to the discharge of flame from the muzzle
- indicates the gun was placed closed to the victim (shots less than 12 inches)
what is tattooing or stippling?
pinpoint hemorrhages due to the discharge of burned powder and metal shards from gun/bullet driven into the skin. typically, a mid to close range effect (up to 5 feet)
what are the two contact marks?
- stellate
- muzzle stamp
what is the stellate contact mark?
when against bone (typically cranium) gasses cannot go through due to bone so will go underneath skin and burn it
what is a muzzle stamp contact mark?
when against soft tissue, gasses can go in causing tissue to damage to body cavity
what evidence can you get from ballistics/GSR?
- fire ammunition/components
- GSR
- incident reconstruction (point of origin)
- trace evidence: fingermarks, bodily fluids etc
what are 3 ways you can collect GSR?
- adhesive tape lifts/pads
- swabs: cotton, polyester, suitable solvents: ethanol, acetone
- vacuums
what are 3 ways you can analyse GSR?
- SEM-EDX
2.GC-MS
3.ICP-MS
