What kind of characteristics do firearms provide?

• A. Both class and individual
• B. Class only
• C. Individual only
• D. None

Answer: (A)

Firearm evidence carries two kinds of characteristics: class characteristics and individual characteristics. Class characteristics are features that group firearms into a model or type—things like caliber, the number of lands and grooves in the rifling, twist rate, and overall internal dimensions. These help narrow evidence to a likely family of firearms rather than pinpointing a single gun.

Individual characteristics are unique marks produced by the specific firearm itself—tiny, idiosyncratic imperfections from manufacturing and wear, such as firing-pin impressions, breech-face marks, extractor marks, and the exact rifling striations on a fired bullet. These marks can link a particular bullet or cartridge case to a specific gun when they match.

So firearms provide both kinds of information: broad class traits that point to a model or type, and unique, individual marks that can tie evidence to a particular firearm. If someone thought only class characteristics mattered, they’d miss the potential for a positive link from the gun’s unique marks; if someone thought only individual marks matter, they’d lose the useful context of identifying the firearm family involved.