Utah Code § 77-21-4
Whenever a judge of a court of record of this state issues a certificate under the provisions of this chapter to obtain the attendance of a witness for the prosecution from without the state in a criminal prosecution or grand jury investigation commenced or about to commence he shall designate therein a suitable peace officer of this state to present the certificate to the proper officer or tribunal of the state wherein the witness is found and to tender to the witness his per diem and mileage fees.
The officer shall exhibit the certificate to the county auditor of the county in which the criminal proceeding is pending and the auditor shall draw his warrant upon the county treasurer in favor of the officer in the amount to be tendered the witness. The officer shall be liable upon his official bond for the proper disposition of the money received.
In all cases in which the officer is required to travel in order to present the certificate and tender fees, his actual and necessary traveling expenses shall be paid out of the fund from which witnesses for the prosecution in the criminal proceeding are paid.
Utah Code § 77-21-4