Which is an example of an individual characteristic of a tool mark?

• A. Manufacturing marks
• B. Size
• C. Unique variations due to use and wear
• D. Shape

Answer: (C)

In tool mark analysis, features are looked at as either class characteristics or individual characteristics. Individual characteristics are the unique imperfections that come from the specific tool’s history of use—its wear, micro-damage, and indistinct striations that accumulate over time. Those unique variations due to use and wear are what can tie a particular tool to a specific mark, because no two tools wear in exactly the same way.

Manufacturing marks, size, and shape describe features common to tools of the same type and production method; they help identify the general category of the tool but aren’t unique to a single item. That’s why the distinct wear patterns, rather than these broad features, are the best example of an individual characteristic.