CASPER, Wyo. (AP) — Wyoming authorities are searching for an inmate who was released from prison early because of a paperwork mistake.

Arthur Penrod was supposed to serve back-to-back sentences for a burglary and aiding an assault. But authorities told the Associated Press  that he was released Tuesday from the Wyoming State Penitentiary in Rawlins after completing the burglary sentence. Someone realized the mistake that night and the search for Penrod began.

Penrod was on parole for the burglary conviction when he was accused of being involved in a beating outside a Casper bar last year with a former fellow inmate. He was convicted in the assault and put back in prison to finish serving the burglary sentence. He then was to serve five to seven years for his role in the assault.