What type of evidence is represented by the number of lands and grooves in rifling?

The number of lands and grooves in rifling is a characteristic that can help identify the type of firearm that produced a particular bullet. This is indicative of class evidence because it provides information that can categorize or group items but does not pinpoint an individual source. Class evidence allows investigators to narrow their focus to a specific type or class of firearm based on the shared features of firearms that fall within that grouping.

For example, if multiple firearms are known to have a specific configuration of lands and grooves, bullets recovered from a crime scene can be traced back to that category of firearms. However, they cannot definitively identify a single gun without further analysis of unique markings, which would fall under the category of individual evidence. Individual evidence is defined by its uniqueness to a specific source, which is not the case with the generic characteristics of lands and grooves, confirming that this type of evidence is classified as class evidence.