Utah Code § 77-13-6: Withdrawal of a plea.

(1) A defendant may withdraw a plea of not guilty at any time before conviction.

(2) A defendant may only withdraw a plea of guilty or no contest upon:

(a) a leave of the court; and

(b) a showing that the defendant did not knowingly or voluntarily make the plea.

(3) A defendant shall make a motion to withdraw a plea of guilty or no contest in accordance with Rule 11 of the Utah Rules of Criminal Procedure.