Firearms, Tool Marks, and Other Impressions

Flashcards of key terms from the lecture notes about Firearms, Tool Marks, and Other Impressions.

Rifling

Inner surface impressed with spiral grooves which guide the bullet through the barrel

Lands

Original bore remain between grooves

Caliber

Diameter of the gun barrel measured between opposite lands

Striations

Random irregularities that run the length of every barrel and are impossible to duplicate exactly therefore are INDIVIDUAL characteristics

Tool mark

Any impression, cut, gouge, or abrasion caused by a tool coming into contact with another object

SICAR

Shoeprint Image Capture and Retrieval-databases of known footwear

Gauge

Diameter of shotgun barrel (12-gauge, 9-gauge; larger the number, smaller the diameter)

Choke

Interior constriction near muzzle end to control shot dispersion

Breechblock

Rear part of a firearm barrel that is struck by spent cartridge

IBIS

Integrated Ballistic Identification System developed for BATF&E to search digitized microscopic images found on both expended bullets and cartridge casings