Question: what horror movies were based on a true story?
Answer: The Exorcist (1973) ...  The Texas Chainsaw Massacre (1974) ...  A Nightmare On Elm Street (2010) ...  Child's Play (1988) ...  The Amityville Horror (2005) ...  Psycho (1960) ...  The Girl Next Door (2007) ...  The Conjuring (2013)