Utah Code § 77-8-1: Order of magistrate -- Grounds -- Arrested suspect's appearance without order.

(1) A magistrate may issue an order requiring a suspect to appear in a lineup when probable cause exists to believe a crime has been committed and there is reason to believe the suspect committed it.

(2) A suspect who has been arrested, and is in custody, may be required by a peace officer to appear in a lineup without a court order.

(3) Upon application of any suspect and a showing of good cause, a magistrate may order a lineup.