Gov. Jerry Brown is blocking parole for an inmate who is serving a life sentence for executing a prison guard 36 years ago during a series of armed robberies.
Michael Martin was convicted of first-degree murder in the 1977 slaying of Correctional Officer Victor Sam in Riverside County.
The state parole board recommended releasing Martin, who is now 53, but the Democratic governor reversed that decision on Friday.
Sam had stopped to help Martin and David Benard, who were pretending to have car trouble to lure passing motorists.
Benard killed Sam with a shotgun after discovering that he was a guard on his way to work at the California Rehabilitation Center in Norco.
It was one day after the officer had brought his infant son home from the hospital.