Despite what some grossly uninformed nay-sayers keep nay-saying - Deliver Us From Evil is indeed based on the real-life story of retired NYPD sergeant Ralph Sarchie, who also worked as a demonologist.
In the wake of a huge push by Sony to promote the film, Entertainment Weekly has released a short documentary about real-life film inspiration Ralph Sarchie, who opens up about some of his bizarre cases, takes the camera crew with him on a case investigation, and includes some crazily creepy footage of an actual exorcism (a Santeria Blood Curse to be specific) from 1992 - keep in mind as you're watching that Sarchie doesn't care if you like him, or if you believe him.
Take the time, and check out the documentary below:
What do YOU think?
(Source: Entertainment Weekly)