“Amityville Horror” killer Ronald DeFeo — who spread terror through Long Island and beyond by slaughtering his parents and four siblings in 1974 — has died, according to state officials.
DeFeo — whose murderous spree served as the inspiration behind the “Amityville Horror” book and movie franchise — died Friday while serving a 25 years-to-life sentence at Sullivan Correctional facility in Fallsburg, New York, a spokeswoman for the state Department of Corrections confirmed. He was 69.
The convicted murderer was transferred to Albany Medical Center and pronounced dead at 6:35 p.m.
An autopsy by the Albany County Medical Examiner’s Office will rule an official cause of death.
DeFeo, whose nickname was Butch, was convicted of killing his mother, father, two sisters and two brothers inside their Amityville home on Ocean Avenue on Nov. 13, 1974.
The then-23-year-old used a .35-caliber Marlin lever-action rifle to slaughter his family members, who were all in bed at the time — dad Ronald DeFeo Sr., 43; mom Louise DeFeo, 43; Dawn, 18; Allison, 13; Marc, 12; and John, 9.
Both parents were shot twice, while the siblings were each shot once. All of the victims were found face-down in bed.
At trial, his lawyer mounted an insanity defense, claiming DeFeo heard voices saying his family was plotting against him.
He was convicted in 1975 of six counts of second-degree murder and received six sentences of 25 years-to-life.
DeFeo was scheduled for a parole hearing in July, online DOC records show.
In a jailhouse interview in 2006, DeFeo claimed he only killed his father, his mother and his eldest sister, Dawn.
The other siblings were murdered by Dawn, before DeFeo killed her, he claimed.
The mass killing served as the inspiration for the 1977 book “The Amityville Horror” and, two years later, the cult classic film “The Amityville Horror,” starring James Brolin and Margot Kidder.
In 2016, the notorious five bedroom, 3 ½ bathroom colonial home where the bloodbath took place hit the market for $850,000 — and went into contract months later.
The original address of the home when the murders took place was 112 Ocean Avenue — but it was eventually changed to 108 Ocean Avenue in order to discourage tourists.
A year after the slaughter, George and Kathy Lutz purchased the home — but left 28 days later after reporting paranormal activity in the home, including “strange sounds, voices and green slime oozing from the walls,” according to real estate site 6sqft.
DeFeo’s death was first reported by Newsday.