Some viewers may be wondering if The Conjuring 3 is based on a true story after watching it in theaters or on HBO Max. If that’s you, allow us to explain the real-life inspiration behind this horror film.

Like every other film in The Conjuring universe, the franchise’s third installment is indeed based on the real-life case files of Ed and Lorraine Warren. The Warrens (played by Patrick Wilson and Vera Farmiga in The Conjuring film series) were paranormal investigators and authors associated with alleged hauntings across America. The Conjuring 3, formally known as The Conjuring: The Devil Made Me Do It, takes inspiration from their involvement in a 1981 murder case in which a man pled not guilty by virtue of demonic possession—hence the film’s title phrase, “the devil made me do it.”

The 1981 case marked the first time in U.S. history in which a defendant submitted such a plea of innocence by reason of possession. The defendant, Arne Cheyenne Johnson, was 19 at the time of the killing. But how was he supposedly possessed in the first place? Well, in the months prior to his trial, Johnson was living with his fiancée Deborah Glatzel, 26, in Brookfield, Connecticut. According to court testimony, Glatzel’s younger brother, 11-year-old David Glatzel, was believed to be possessed by 43 demons himself—and the story goes that one of those demons eventually entered Johnson.

The exchange seemingly occurred after the Glatzel family invited paranormalists Ed and Lorraine Warren to carry out an exorcism on David. The couple claimed they did so successfully with the help of priests from the Catholic Church. Still, the boy’s exorcism took place for several days, during which it was believed that one of the demons that left David entered Johnson as a host. Before David’s exorcism was through, the boy even predicted the murder that Johnson would eventually commit.

Just several months later, Johnson brutally murdered his landlord, Alan Bono. Johnson became enraged after seeing Bono grab inappropriately at his fiancée Debbie’s nine-year-old cousin, Mary. When he refused to let her go, Johnson reportedly stabbed the man repeatedly. Ultimately, Johnson was convicted of first-degree manslaughter and sentenced to 10 to 20 years in prison.

The Conjuring: The Devil Made Me Do It is now in theaters and available to stream on HBO Max.

Our mission at STYLECASTER is to bring style to the people, and we only feature products we think you’ll love as much as we do. Please note that if you purchase something by clicking on a link within this story, we may receive a small commission of the sale.