Sitting in the Bel-Nor neighborhood of St.Louis, Missouri is a house with a dark history. Its brick exterior and white shutters makes it just as average and innocuous as the homes that surround it, but this was once the home of Roland Doe - the boy who would go on to inspire William Peter Blatty’s 1971 novel “The Exorcist,”and subsequently William Friedkin’s film of the same name.