On the evening of November 14, 1974, police were called to a house in Amityville, Suffolk County, New York after 23 year old Ronald ‘Butch’ DeFeo burst into a local bar and declared his entire family had been shot. There, the police discovered six dead bodies - the entire DeFeo family save one. Mother and father, two brothers and two sisters had been shot with a high-powered rifle as they slept in their beds.
When Ronald DeFeo was questioned, he seemed distraught, and he suggested that the man responsible might be Louis Fatini, a Mafia mobster whom Butch claimed had a grudge against his father.

Butch was a hot-tempered young man, a drug addict with  known interest in firearms - he had once turned a loaded shotgun on one of his best friends. On more than one occasion, he had threatened to kill his father - the last occasion being less than a week before the killings. Although Butch provided a detailed alibi, some of it did not make sense.

Eventually the truth emerged. Early on the morning of November 14, Butch had taken his .35 calibre Martin rifle, gone to his parents’ bedroom and fired two shots into his father, and two shots into his mother. He then moved on to his brothers’ bedroom and killed both John and Mark with a single shot. Finally he entered the room where his sisters slept and killed them.

At his trial a year later, Butch had claimed that strange voices in his head compelled him to commit the murders and his counsel attempted to enter a plea of insanity. Butch told the court: “When I get a gun in my hand, there’s no doubt in my mind who I am. I am God.” There was clear evidence, however, that in the aftermath of the killing he had acted with considerable cunning - throwing his own bloodstained clothes down a storm drain. This was not considered by the jury to be an action of a madman. He was found guilty and sentenced to death from 25 years to life on all six counts of murder.