SACRAMENTO, Calif. (AP)-A serial killer whose five victims included two women he married has died on California’s death row.

Authorities said Monday that 73-year-old Phillip Carl Jablonski was found unresponsive in his San Quentin State Prison cell on Friday.

His cause of death is awaiting an autopsy, but he had been assigned to a single cell.

A San Mateo County jury sentenced him to death in 1994 for the murders of his 46-year-old wife and her 72-year-old mother.

Carol Spadoni had married him while he was in prison for murdering a previous wife in 1978. He had a long history of violence dating to his trying to kill his first wife in the 1960s.