Utah Code § 53-13-110.5

If a peace officer, or the officer's employing agency, records an interview of a minor during an investigation of a violation of Section 76-5-402.1, 76-5-402.3, 76-5-403.1, 76-5-404.1, or 76-5-404.3, the agency shall retain a copy of the recording for 18 years after the day on which the last recording of the interview is made, unless the prosecuting attorney requests in writing that the recording be retained for an additional period of time.