CARSON CITY, Nev. (AP) — Officials say a 65-year-old Nevada prison inmate who was serving a life sentence for robbery, sexual assault and failure to register as a sex offender has died behind bars.

The Nevada Department of Corrections says Eugene Fitzgerald was pronounced dead Monday at the prison medical facility at Northern Nevada Correctional Center in Carson City.

A cause of death wasn't immediately disclosed pending an autopsy.

Prison records showed that Fitzgerald also used the name Jean Nupe and was sentenced to state prison in October 2014 in Las Vegas.