Answer:
Corpus delicti.
Explanation:
The Corpus Delicti a term that is used to describe the basis of a crime (it's literal meaning, from Latin, means "body of the crime"). This principle means, in other words, that the crime has to be proven before convicting the suspect of the crime. Therefore, Bob can't be convicted for, allegedly, stealing 30 televisions given that no one had reported them stolen.