16-5 Collection and Preservation of Firearms Evidence Unit 16 - Firearms, Tool Marks, and Other Impressions

restoring serial numbers Criminalist can restore serial numbers is removed or obliterated by grinding rifling or punching.

stamp zone The metal crystals in the stamp zone are placed under permanent strain then extends a short distance beneath the original numbers.

chemical etching Serial numbers can be restored through chemical etching.

Barrel The suspect firearm should never be picked up by inserting an object into its barrel because this practice may alter the striation markings and test fire bullets.

Locate and record Before unloading a suspect weapon record the weapon’s hammer position safety position location all fired ammunition unfired ammunition

field investigator The primary concern of the field investigator Protection of class markings individual markings bullets and cartridge casings is recovery and bullets and cartridge casings.