Ronald DeFeo was born on 26 September 1951 in Brooklyn, New York City, New York, USA. He was married to Nissa Burkhalter, Tracey Defeo and Barbara Puco. He died on 12 March 2021 in Albany, New York, USA.
Following his arrest in 1974, he claimed in his official testimony that he had heard a disembodied voice telling him to murder his family, though after much deliberation it was later revealed the claim was merely a ploy, as a part of an insanity defense plea led by his defense attorney William Weber.