(a) Except as provided in (b) of this section, a person who has been directed by another who that person reasonably believes to be a peace officer to assist in making an arrest or terminating or preventing an escape may use nondeadly force when and to the extent the person reasonably believes it necessary to carry out the peace officer's direction. A person may use deadly force under this section only when the person reasonably believes it necessary to carry out the peace officer's direction to use deadly force. (b) The use of force under (a) of this section is not justified if the person believes that the peace officer is not justified in using that degree of force under the circumstances.
Alaska Legal Code