The Conjuring 3: The Devil Made Me Do It Is Based on a True Story, and Oh, Hell No

From the Enfield poltergeist to the terrifying Annabelle doll, the Conjuring universe has always drawn from actual stories. Headed to HBO Max this June, The Conjuring 3: The Devil Made Me Do It takes a step in a true-crime direction, following paranormal investigators Ed and Lorraine Warren (Patrick Wilson and Vera Farmiga) as they delve into Arne Cheyenne Johnson and David Glatzel's demonic possession case. If you're a paranormal enthusiast, chances are you've likely heard of Johnson's "The Devil Made Me Do It" story. After fatally stabbing his landlord, 19-year-old Johnson tried to use demonic possession as a defence in court.

Before you check out The Conjuring's interpretation of this strange true story, here's what you need to know about the murder and how the Warrens got involved in the case.

How the Murder Unfolded

The murder took place in February 1981 in the small town of Brookfield, CT, which had never seen a murder after nearly 200 years of existence. Cheyenne Johnson, a tree arborist, was arguing with his 40-year-old landlord, Alan Bono. All of a sudden, Johnson, who had no prior criminal record, repeatedly plunged a five-inch pocket knife into Bono's chest and killed him. Johnson's fiancée, Debbie Glatzel, watched in horror as the murder unfolded, but she would later come to his defence in court.

How the Warrens Became Involved

To get a full picture of the supernatural background of this case, we need to rewind to a year before the murder. Since the summer of 1980, Glatzel's 11-year-old brother, David, had been seeing "a man with big black eyes, a thin face with animal features and jagged teeth, pointed ears, horns, and hoofs." He writhed on his bed, shouting, spitting, and kicking — David apparently flinched from invisible knife cuts and invisible hands choking him. Glatzel asked Johnson to move in with her family to help with her brother's situation. Her parents even brought in a priest to bless the house, but nothing seemed to work. They eventually recruited the Warrens, who informed them that there were 43 demons inside David.

Johnson and Glatzel moved out of Glatzel's family home because David's troubles and behaviour became too much for them. According to Johnson, he dared David's demons to enter his own body during an exorcism and killed his landlord while he was possessed. Before Bono's murder, Glatzel recalled her boyfriend entering strange trances. Four months before the murder, Lorraine apparently even called the police to warn them that there was danger in the Glatzel household. She later helped Gerald Brittle write The Devil in Connecticut, which closely follows this odd case.

What Happened in Court and Afterward

Several months after Bono's death, Johnson pleaded not guilty to his murder charge, claiming that the devil made him do it. A superior court judge wouldn't allow Johnson's defence of innocence by demonic possession, so things didn't pan out in court. Johnson was convicted of first-degree manslaughter, spending five years in prison. He later married Glatzel in 1984 while still serving his sentence. The couple have backed up the Warrens' version of the story, but Glatzel's siblings, David and Carl, later claimed the Warrens fabricated the demonic possession hoax to take advantage of David's mental illness.