Which type of evidence includes bullets, cartridge casings, and shotgun shells?

• A. Trace evidence
• B. Toolmark evidence
• C. Impression evidence
• D. Firearm evidence

Answer: (D)

Bullets, cartridge casings, and shotgun shells are directly produced by firearms and are analyzed within the realm of ballistics. Their primary relevance is linking a crime to a specific weapon or to exclude it, because they carry distinctive markings from the firearm. Bullets pick up rifling marks from the barrel, while cartridge cases show firing-pin, extractor, and ejector marks that can be matched to a particular gun. Because these items come from the firearm and its ammunition, they are classified as firearm evidence. This distinguishes them from trace evidence (small particles like fibers or gunshot residue), toolmark evidence (marks from tools on surfaces), and impression evidence (indentations like footprints or tire tracks).