In the classic Psycho Robert Bloch rooted the character of Norman Bates in the actions and theories surrounding Ed Gein, an actual serial killer. While Norman was based off of Ed, they weren’t the same person (as is evident by their different names.) Likewise, Blatty would base Regan MacNeil in The Exorcist off of another case while eschewing several important details. Ketchum’s Joyride is likewise grounded in real events without exploring those roots in any great detail.
Yet in 1977, entertainment writer Jay Anson broke the mold by penning the ‘true’ story of the Lutz/DeFeo house located at 112 Ocean Avenue, Amityville, New York.