FBI rules for handling evidence
Evidence was proof that an event, such as a crime, had occurred and the details thereof.
In 2265, during a briefing in which the mutating Gary Mitchell's abilities were the subject of discussion, Spock asked Doctor Elizabeth Dehner if she had seen evidence of unusual extrasensory perception powers. She offered as evidence that Mitchell could control certain autonomic reflexes and could read very fast and retain more than was usual of what he had learned from reading. (TOS: "Where No Man Has Gone Before")