Which of the following is a region of interest on an unfired cartridge?

• A. Breech face marks
• B. Drag mark
• C. Primer
• D. Firing pin impression

Answer: (C)

On an unfired cartridge, the primer region is the part that can carry identifiable markings before any discharge occurs. The primer is a distinct, pre-existing component with its own machining and seating marks from manufacturing and assembly, so forensic examiners can compare it to known samples without firing the cartridge. The other features listed—breech face marks and firing pin impressions—are created when a cartridge is chambered and fired, leaving impressions on the cartridge case or primer only after ignition; drag marks likewise arise from the cartridge or bullet interacting with the firearm or barrel during firing and ejection. Because nothing in those areas is formed prior to firing, they aren’t regions of interest on an unfired cartridge.