Utah Code § 76-2-401: Justification as defense -- When allowed.

(1) Conduct which is justified is a defense to prosecution for any offense based on the conduct. The defense of justification may be claimed:

(a) when the actor's conduct is in defense of persons or property under the circumstances described in Sections 76-2-402 through 76-2-406 of this part;

(b) when the actor's conduct is reasonable and in fulfillment of his duties as a governmental officer or employee;

(c) when the actor's conduct is reasonable discipline of minors by parents, guardians, teachers, or other persons in loco parentis, as limited by Subsection (2);

(d) when the actor's conduct is reasonable discipline of persons in custody under the laws of the state; or

(e) when the actor's conduct is justified for any other reason under the laws of this state.

(2) The defense of justification under Subsection (1)(c) is not available if the offense charged involves causing serious bodily injury, as defined in Section 76-1-101.5, serious injury, as defined in Section 76-5-109, or the death of the minor.