Utah Code § 76-2-307: Voluntary termination of efforts prior to offense.

It is an affirmative defense to a prosecution in which an actor's criminal responsibility arises from the actor's own conduct or from being a party to an offense under Section 76-2-202 that prior to the commission of the offense, the actor voluntarily terminated the actor's effort to promote or facilitate its commission and either:

(1) gave timely warning to the proper law enforcement authorities or the intended victim; or

(2) wholly deprives the actor's prior efforts of effectiveness in the commission.