What evidence would be least likely found at a crime scene?

Witness testimony is least likely to be found at a crime scene because it is not a physical piece of evidence like clothing, fingerprints, or tools. Instead, it is an account provided by individuals who have observed events related to the crime. While witness testimony can be crucial in investigating and prosecuting cases, it occurs after the event has transpired and relies on human memory and perception, which can vary widely. In contrast, the other types of evidence listed are tangible and can often be collected directly from the scene, providing concrete information regarding the crime and the individuals involved.