Cartridge casings were found at two different recent crime scenes. Refer to photographs labeled A–L on the following pages. Three suspects were apprehended. Police test-fired firearms belonging to the suspects and compared firing pin marks and other marks on the cartridge casings with those marks on the crime-scene spent cartridge casings.
When cartridge casings are recovered from a crime scene, they are photographed and compared with National Integrated Ballistic Information Network (NIBIN) database records to determine whether they are consistent with any cartridge casings found at previous crime scenes. The NIBIN database allows investigators to link a series of crimes to the same perpetrator. Spent cartridge casings bear identifying marks, including the name of the manufacturer, caliber, ejector/extractor marks, breechblock marks, and firing pin impressions. In this activity, you will compare marks on the suspect’s spent cartridge casings with the marks on cartridge casings found at a crime scene. Include the following:
