Because the bore of a firearm has small imperfections
and the bore is harder than the bullet of a cartridge, it will always leave
striations. These markings will always be the same for any bullet fired from a
particular gun. IBIS compares the item being entered into the system to all
previous information entered, in an attempt to identify the firearm used.
Ballistics is a science that deals with the motion of projectiles.
Firearms cartridges are made up of the lead projectile called a bullet; the
casing; powder; and a primer or charge. Investigators look for shell casings at
any crime scene that involves a shooting so they can match the striations from
the spent cartridge to the murder weapon, if it is ever found.
There are several reasons why the condition of a
bullet casing will prevent a ballistics expert from making a comparison. I know
this because I’ve watched so many CSI reruns, and read HONOLULU CSI.
What situations would make it impossible to run a
casing through IBIS?
