increasing for everybody to deal with. >> superintendent craig hanks has been working at the prison since it opened in 1992. >> this is a multi-security level facility. it's a large facility. we're on over 500 acres of property. the perimeter is approximately a mile and a half around the facility. we have maximum security, medium security and minimum security offenders. what probably sets us apart is the different segregation units. >> offenders who assault staff or other inmates are moved to the secure housing unit, a prison within the prison, known as the shu. >> there have been discipline problems, they've been assaulted and they've had issues at other facilities. so they send them here. >> designed to look and function like pelican bay, a maximum security prison in california, the shu is composed of windowless, concrete cells measuring 7 by 12 feet. of the 288 inmates housed here, 179 have been diagnosed by psychiatric staff as mentally ill.