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.