Answer:
Failure-of-proof defense
Explanation:
Failure of Proof Defense can be defined simply as defendant's acquittal is the result of the prosecution failing to prove one or more of the elements of a crime (Actus Reus, Mens Rea) or leaving reasonable doubt in the mind of the jury.
It usually develops or creates doubt in one or more elements of the offense thereby obstructing the prosecution from meeting its burden of proof.