Deliver Us from Evil: 'inspired' and adapted from the book by Ralph Sarchie and Lisa Collier Cool by Scott Derrickson and Paul Harris Boardman; directed by Scott Derrickson; starring Eric Bana (Sergeant Sarchie), Edgar Ramirez (Father Mendoza), Olivia Munn (Jen Sarchie), and Joel McHale (Detective Butler) (2014): Real-life person-type Ralph Sarchie is indeed a real former NYPD cop turned paranormal investigator. He comes from the school of the Warrens (remember the 'real' investigators in The Conjuring?), which means that charitably speaking, I don't believe a word of his paranormal adventures.
However, as a quick perusal of the IMDB page for this movie reveals, this film, 'inspired by actual case files,' is pretty much entirely fictional anyway. The case that Sarchie, still a cop, and Father Mendoza find themselves investigating has been invented whole-cloth by the film-makers so as to give Sarchie an exciting origin story. I'm assuming they were hoping for a Conjuring-level hit and a subsequent series of Sarchie-centric horror movies. No such luck. I hope.
As casting decisions go, this is a comedy of errors. Eric Bana struggles mightily to play a New York cop, Olivia Munn seems to have wandered in from another movie, Edgar Martinez lacks all plausibility as a sexy, "undercover" (the character's word, not mine) Roman Catholic priest, and Joel McHale plays Joel McHale playing a wise-cracking cop in what may be a dream sequence from Community. Many major concepts, including the Iraqi origin of the demons, are simply lifted from The Exorcist.
Most hilariously, the film-makers apparently are a-scared of The Doors. Doors music and lyrics show up repeatedly as elements in the various horrors being perpetrated by the demons. Is Satan a Doors fan? Is he sitting on the bus sucking on a humbug? I have no idea. This is dreadful, stupid horror. Not recommended.