Ronald DeFeo Jr., the convicted killer whose 1974 murders spawned the "Amityville Horror" franchise, died last week while serving a 25 years-to-life prison term, officials said Monday.
DeFeo, 69, was pronounced dead at 6:35 p.m. Friday at the Albany Medical Center, state corrections officials said in a statement.
It wasn't clear why DeFeo, who was serving his sentence at Sullivan Correctional Facility, was hospitalized, and a cause of death was still being determined by the medical examiner's office in Albany County, officials said.
DeFeo was 23 when he shot his parents, two sisters and two brothers at their home in Amityville, on Long Island's south shore, on Nov. 13, 1974.
During his trial, DeFeo pursued an insanity defense and claimed that he had heard voices telling him to kill his family. He was convicted in 1975 of six counts of second-degree murder.
The home and the killings became the basis of the horror movie classic "The Amityville Horror" after another family briefly lived there for about a year after the killings and claimed the house was haunted.
A book and the resulting film franchise — including the 1979 original with James Brolin, Margot Kidder and Rod Steiger; several sequels; and a 2005 remake with Ryan Reynolds — portrayed a home with strange voices, walls that oozed slime, furniture that moved on its own and other supernatural features.
The home was listed as recently as 2016 for $850,000.
DeFeo unsuccessfully sought a retrial in 1992, claiming that his 18-year-old sister killed the five other family members and that he then shot her.
"I loved my family very much," he said at a 1999 parole hearing, where he also said he had gotten married while in prison.
The corrections department said it couldn't disclose why DeFeo was hospitalized, citing health privacy laws. The Albany County Coroner's Office, which is responsible for determining what caused his death, said it doesn't release such information except to relatives of the dead.