Death row inmate Richard Ramirez, also known as the "Night Stalker," died of cancer, according to the Marin County coroner's office.
Ramirez, 53, died on June 7 at Marin General Hospital in Greenbrae, Calif.
The Coroner released the cause of the death of the infamous serial killer Monday, saying he died from "complications of B-cell lymphoma." Also noted by the coroner was chronic substance abuse and a chronic hepatitis “C” viral infection
Ramirez had been on death row at San Quentin State Prison since he was convicted in 1989 of 13 murders. He was moved to Marin General in the days ahead of his death to be treated for liver failure.
The slayings and sexual assaults terrorized Southern California in 1984 and 1985 with reports of Satanic symbols at bloody crime scenes and a killer who entered through unlocked windows and doors -- a method that led to his original nickname, the "Walk-In Killer."
Some of the victims were shot to death, others were strangled or had their throats slashed.
Ramirez is the 59th condemned inmate to die from natural causes on death row since California reinstated capital punishment in 1978.
Twenty-two inmates have committed suicide on death row, 13 have been executed in California and one inmate was executed in Missouri, according to the Department of Corrections and Rehabilitation. Six have died from other causes, according to the department.
There are currently 735 offenders on California's death row.