How is class evidence useful?

Class evidence is evidence that can be linked to a group of people rather than individual evidence which can only be linked to one person. Although class evidence can help solve cases, its not guaranteed to solve it. An example of class evidence is if a shoe print is left behind and the only thing they can make of it is the shoe size or make, that would be a class characteristic since many other people may have that same shoe size and make. The shoe print may also be individual evidence due to the fact that not everyone walks the same. If the shoe has wear on a specific part then we can infer that the suspect walks with more weight on that part of there feet.