There are many horror movies based on true stories -- more than you may realize! While some movies that are based on (or inspired by) true stories very loosely follow the original account of an incident, others may be more realistic than you care to know! Here are a few horror movies based on true stories that you may want to think twice about before watching!
Of all the horror movies based on true stories that I have seen, The Exorcist has to be one of the creepiest. This movie is about a young girl who is possessed by a demon and is based on a story about a young boy who was deemed to be possessed by, and later exorcised, of a demon. I watched a documentary of the boy's possession, and I am pretty sure the documentary is scarier than the movie itself!