What True Stories Were So Messed Up, They Became Horror Movies?

I don't think I can ever go scuba diving after watching Open Water.

It's spooky season, and in honor of the one month a year that I spend scaring myself in every way possible, this is the perfect time to look into some true stories that were so scary, they became movies.

Dimension films

If you're a horror lover like me, you already know that seeing that "Based on a True Story" title card ramps up the fear. So, we want to know, what are some crimes or scary stories that were so messed up, they became movies?

American International Pictures

Maybe you love how terrifying The Conjuring is, which is based on the true story of paranormal investigators Ed and Lorraine Warren, who looked into the haunting of the Perron house. The film even used interviews of the Perron family in its marketing process.

Warner Bros. Pictures

Or perhaps you're horrified that Open Water — a film about a couple who was accidentally left by their scuba-diving group and then eaten by sharks — is actually based on a true story.

Lions Gate Films

Although, it's unlikely that the couple the movie is based on was actually eaten by sharks. They were left in the ocean and likely died of dehydration, which is just as terrifying.

Maybe you can barely believe that The Exorcist was actually based on the true story of a 14-year-old boy who experienced a months-long exorcism in 1949. Obviously, the book and subsequent movie took some liberties in how they portrayed it.

Warner Bros.

Either way, we want to know! What horror movies based on wild, true stories (however loosely) absolutely terrify you, and why? Tell us in the comments below for a chance to be featured in a future BuzzFeed Community post.