Laboratory Analysis

Abstract

Firearm examiners conduct a variety of laboratory examinations. They test fire and examine firearms of all types for function, safety, and alteration; they microscopically compare fired bullets and cartridge cases. They examine gunshot-residue patterns and shotgun pellet patterns; they sometimes restore obliterated serial numbers; and they conduct toolmark examinations. The focus in this article is on the procedures used for firearms and fired ammunition examinations and on their conclusions, all in the context of scientific validity and uncertainty. A short discussion of recent developments is also included.