Which statement about class characteristics is correct?

• A. A trait that allows the item to be compared with a group and included or excluded.
• B. A trait that uniquely identifies an individual item.
• C. A trait that can only be observed in DNA.
• D. A trait that is undefined.

Answer: (A)

Class characteristics describe traits that place evidence into a group, allowing comparison with a class of sources to include or exclude. They help you decide whether evidence could have come from a particular class, like a specific caliber or fabric type, rather than proving it came from one exact item. Because these features denote a category rather than a unique source, they can narrow possibilities but cannot identify a single object. For example, the caliber of a bullet or the general type of tool mark can link evidence to a class, while individual characteristics—unique wear or random defects—are needed to pinpoint a single item. DNA is not the only domain where class characteristics apply; many materials exhibit class traits that guide narrowing down sources. So the statement describes how class characteristics function: it’s about grouping and comparing to include or exclude members of a class. The other ideas would imply unique identification, restriction to DNA, or being undefined, which don’t fit how class characteristics operate.