AFTE Store - The Identification of Consecutively Manufactured Extractors

Caspian Arms, Ltd. produced ten consecutively manufactured extractors for use in a Colt, Model 1911A1 semi-automatic pistol. These extractors were used in the same semi-automatic pistol to produce samples of known and unknown cartridge casings. A group of firearm and toolmark examiners were given test sets of these cartridge casings to attempt to make the correct associations between the known and unknown casings. Each examiner was to receive 12 unknown casings in addition to standards for the ten consecutively manufactured extractors, with each known having at least one unknown associated with it. This study showed that when a proper scientific approach is applied the correct identifications could be made and the extractors could be distinguished from each other regardless of the fact that they were consecutively manufactured.