Oklahoma prison officials say an inmate on the state's death row has apparently taken his own life.

Oklahoma Department of Corrections spokesman Matt Elliott says 35-year-old Jeremy Williams of Tulsa was found dead in his cell at the Oklahoma State Penitentiary. 

Authorities say members of the prison's staff discovered Williams' body while conducting a head count on death row at about 11:14 p.m. Saturday.

Williams was sentenced to death for the June 22, 2004, murder of a bank teller during a robbery in Tulsa. The victim, 26-year-old Amber Rogers, was fatally shot during a robbery in which two other people, a customer and a second bank employee, were wounded.

Oklahoma hasn't carried out executions for more than three years after experiencing problems with its lethal injection protocol.

The Associated Press contributed to this report.