ABSTRACT
Firearms have been around since black powder was invented back in the 13th century. The difference between a semi and an automatic firearm is the number of bullets that are projected every time the trigger is pulled. In a semi-automatic firearm, only one bullet is fired for every trigger pull. Handguns, rifles, and machine guns mostly use a cartridge to fire a bullet. A cartridge is a case that holds together the primper assembly or priming depending on whether it is a centerfire or rimfire cartridge, respectively, the propellant, and the bullet. The class and individual characteristics transferred by firearms come in the form of striations and impressions to cartridges and shotshells. A point worth mentioning is a firearms examiner examines physical evidence and does link a bullet and a cartridge case to a person. A firearm examiner can identify a bullet or a cartridge case to a firearm and does not know whether a specific person operated a firearm.
