PHOENIX (AP) – An inmate who took two prison guards hostage in one of the longest prison standoffs in the nation’s history was sentenced Friday to 16 consecutive life sentences.

Ricky Wassenaar, 42, was convicted last month on 19 charges including kidnapping, sexual assault and aggravated assault for his role in last year’s 15-day hostage standoff at the Arizona State Prison Complex-Lewis.

Wassenaar, who acted as his own attorney, was acquitted on one count of attempted second-degree murder. After the verdicts were read, Wassenaar repeatedly said, “worst verdicts I ever heard.”

The standoff began Jan. 18, 2004, after Wassenaar and another inmate, Steven Coy, overpowered guards and staff in the prison’s kitchen using makeshift knives.

Wassenaar put on an officer’s uniform and tricked guard Jason Auch into letting him into an armed watchtower. Coy was let in later.

The inmates released Auch after a week.

The second guard, Lois Fraley, was held during the entire standoff. She has publicly said she was raped by both inmates.

Wassenaar was already serving 28 years for armed robbery and assault. His sentence Friday also included 25 years on top of the life sentences.

Coy pleaded guilty last year to kidnapping, assault, sexual assault and other charges. He is serving seven life sentences in Maine.

The Arizona State Prison Complex-Lewis, west of Phoenix in Buckeye, houses 4,400 inmates, most convicted of felonies such as manslaughter and aggravated assault.