California police killer dies of unknown causes on death row

The killer of a Garden Grove police officer has died of unknown causes in his cell at San Quentin State Prison.

Corrections officials say 71-year-old John Brown was found unresponsive Sunday evening.

Brown was sentenced to death in Orange County in 1982 for the murder two years earlier of 27-year-old Officer Donald Reed. Brown shot at Reed and two other officers as they tried to arrest him on a felony warrant.

He was convicted of first-degree murder, assault with intent to murder and assaulting a police officer.

Gov. Gavin Newsom earlier this year imposed a moratorium on executions.

California has carried out 13 executions since 1978. Another 80 condemned inmates have died from natural causes.

The nation's largest death row holds 734 offenders.