An evaluation of the discriminating power of an Integrated Ballistics Identification System Heritage™system with the NIST standard cartridge case (Standard Reference Material 2461).

Through analysis and comparison of firing pin, breech face, and ejector impressions, where appropriate, firearm examiners may connect a cartridge case to a suspect firearm with a certain likelihood in a criminal investigation. When a firearm is not present, an examiner may use the Integrated Ballistics Identification System (IBIS), an automated search and retrieval system coupled with the National Integrated Ballistics Information Network (NIBIN), a database of images showing the markings on fired cartridge cases and bullets from crime scenes along with test fired firearms. For the purpose of measurement quality control of these IBIS systems the National Institute of Standards and Technology (NIST) initiated the Standard Reference Material (SRM) 2460/2461 standard bullets and cartridge cases project. The aim of this study was to evaluate the overall performance of the IBIS system by using NIST standard cartridge cases. By evaluating the resulting correlation scores, error rates, and percent recovery, both the variability between and within examiners when using IBIS, in addition to any inter- and intra-variability between SRM cartridge cases was observed.