Chapter 10: Firearms Flashcards
trajectory analysis
internal, external, terminal
internal ballistics
at crime lab by firearms examiner, function and operation of weapon, bullets, casings. ejection patterns and GSR.
terminal ballistics
by pathologist/ME. defines path of bullet, entry/exit wounds, range determinations.
range determinations
GSR known/questioned tested at different ranges.
loose contact
close proximity to skin, small gap.
close contact
pressed to the skin.
near contact
no more than 5 inches from wound.
indeterminate range
no characteristics, no conclusions.
intermediate range
5-40 inches from wound.
external ballistics
crime scene analyst at scene, path of bullet through aspects at the scene, defines possible and impossible trajectories.
trajectory kits
trajectory rods, centering guides, angle finders, sometimes lasers.
recover bullets
in paper, do not clean or mark
evidence with biological fluids
air dried and sent to lab
cartridge case recovery
package each in own case unless found at same location
slug
from a shotgun shell
bullets and cartriges
not in same packaging
primer engaged by firing pin
can be traced back to the gun
GSR
collected within first three hours, highly unlikely to be collected 3+ hours if they washed their hands
body processed for GSR
paper bags around hands
serial number
always found on frame of gun, some are hidden
serial numbers can be restored through
manually decrypted, chemically restored, automatically decoded
tool mark evidence
most common in burglaries, sometimes possible to prove that parts of tools came from certain tools
