Richard Ramirez, the US serial killer known as the Night Stalker, who left satanic signs at murder scenes and mutilated victims' bodies during a reign of terror in the 1980s, has died in hospital.
Ramirez, 53, had been taken from San Quentin's death row to hospital, where authorities said he died of liver failure on Friday.
He had been on death row for decades and was awaiting execution, even though it has been years since anyone has been put to death in California.
At his first court appearance, Ramirez raised a hand with a pentagram drawn on it and yelled: "Hail Satan."
His marathon trial, which ended in 1989, was a horror show in which jurors heard about one victim's eyes being gouged out and another's head being nearly severed. Courtroom observers wept when survivors of some of the attacks testified.
Ramirez was convicted of 13 murders that terrorised southern California in 1984 and 1985 as well as charges of rape, sodomy, oral copulation, burglary and attempted murder.
Satanic symbols were left at murder scenes and some victims were forced to "swear to Satan" by the killer, who entered homes through unlocked windows and doors.
Ramirez was finally caught in 1985 after he was recognised, and beaten up, by residents of an east Los Angeles neighbourhood while attempting a carjacking. His picture had appeared in the media that day.
His trial took a year, but the entire case – which was bogged down in pretrial motions and appeals – lasted four years, one of the longest criminal cases in US history.
Because of the notoriety of the case, more than 1,600 prospective jurors were called.
After his conviction, Ramirez flashed a two-fingered "devil sign" to photographers and muttered a single word: "Evil."
On his way to a jail bus, he sneered in reaction to the verdict, muttering: "Big deal. Death always went with the territory. See you in Disneyland."
The black-clad killer, unrepentant to the end, made his comment in an underground garage after a jury recommended the death penalty for his gruesome crimes.
Ramirez, a native of El Paso, Texas, had a following of young female admirers who came to the courtroom regularly and sent him love notes.
Some visited him in prison, and in 1996 Ramirez was married to a 41-year-old freelance magazine editor, Doreen Lioy, in a visiting room at San Quentin prison.
Relatives called Lioy a recluse who lived in a fantasy world.
In 2006, the California supreme court upheld Ramirez's convictions and death sentence. The US supreme court refused in 2007 to review the convictions and sentence.
Two years later, San Francisco police said DNA linked Ramirez to the 10 April 1984 killing of nine-year-old Mei Leung. She was killed in the basement of a residential hotel in San Francisco's Tenderloin neighbourhood where she lived with her family. Ramirez had been staying at nearby hotels.
He was previously linked to killings in northern California. He was charged in the shooting deaths of Peter Pan, 66, and his wife, Barbara, in 1985 just before his arrest in Los Angeles, but he was never tried in that case.