DeFeo, who shot and killed his mother, father, two sisters, and two brothers while they slept in their Suffolk County home in Amityville 1974, died on Friday, March 12, New York State officials confirmed.
The 69-year-old DeFeo was serving his life sentence in the Hudson Valley at Sullivan Correctional Facility after being convicted of six counts of murder in the second degree, state officials said,
The official cause of death will be determined and released by the Albany County Medical Examiner’s Office pursuant to County Law.
The case, which spawned a book and later the movie "The Amityville Horror," captured the country's imagination after DeFoe, who went by the nickname Butch, was convicted on six counts of murder for the killings in the family's Ocean Avenue home in Amityville.
The movie told the story of the family who bought the house following the murders and their claims of being terrorized by paranormal activities after moving in.
During his trial, police said DeFeo shot each of his family members with a .35-caliber rifle, shooting each of his parents twice and his siblings once each.
He pleaded insanity during the trial, where there was some speculation that he had drugged the family before killing them.
DeFeo was convicted on Nov. 21, 1975, and sentenced to six sentences of 25-years-to-life.
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