The True Story Behind The Conjuring: The Devil Made Me Do It

Although this case is without doubt sensational and will make for a thrilling movie, over the years cracks have opened up in the narrative.

Most of the opposition comes from the now adult David Glatzel and his older brother Carl, who dispute every single one of the claims made by The Warrens and their family. Upon the republication of the book in 2006, the Glatzel brothers sued Lorraine Warren and the publishers for "defamation of character."

The two men claim that their religious family failed to understand young David's mental health problems, choosing spiritual help instead of psychological treatment. Furthermore, the Glatzel brothers slate Ed and Lorraine Warren for promising books, movies and money if the family continued to play along during the trial.

Of Arne Johnson and the murder, the brothers claim he was often violent, but defend his crime saying Alan Bono had taken Johnson's young sister hostage and boasted he would do "terrible things" to her.

Whatever the case, the resultant story is certainly fascinating, and the forthcoming film is sure to scare up a tidy box-office return.

The Conjuring: The Devil Made Me Do it opens May 28th in the UK and June 4th worldwide.