There is something more disturbing about a horror film that begins with the phrase “based on a true story.” Okay, sure, slashers and haunted houses are terror-inducing, but when some aspect of the nightmare is based on actual events? That’s an entirely new plane of terror. So go ahead and grab a snack (and perhaps leave a lamp on), because here’s a countdown of 10 horrifying horror movies based on real-life happenings—disclosed in reverse order, because suspense is sweeter.
10. Open Water (2003)
Ever feared becoming lost on holiday? Tom and Eileen Lonergan lived that horror in real life when they were left stranded by accident while on a scuba dive in the Great Barrier Reef off Australia. They were never heard from again, and the film doesn’t flinch at the despair—or the sharks—that closed in around them.
9. Verónica (2017)
What starts as a safe séance soon becomes one of Spain’s most notorious paranormal cases. Based on Estefanía Gutiérrez Lázaro, a young woman who mysteriously died after experimenting with a Ouija board, this horror film reveals how things can turn out when you open the door to the unknown.
8. 10 Rillington Place (1971)
Serial murderer John Christie made his London home a horror show, killing several victims and even accusing his neighbor of two of them. This dark film version exposes not just Christie’s atrocities but also the heartbreaking miscarriage of justice that ensued.
7. Audrey Rose (1977)
Reincarnation isn’t just a philosophical debate—it was personal for author Frank De Felitta, whose young son reportedly displayed memories of another life. That unsettling idea inspired Audrey Rose, a film about a girl who might not truly be herself at all.
6. Black Water (2007)
Find sharks intimidating? Have a go at being pursued by a crocodile in the outback of Australia. Loosely inspired by a true attack, this survival horror shows that nature itself can be the greatest killer of all.
5. The Entity (1982)
Doris Bither reported her house was the location of ongoing attacks by unseen forces, a case that engaged paranormal researchers. Although the movie plunges the horror to appalling heights, the actual story is one of the spookiest in supernatural history.
4. The Mothman Prophecies (2002)
During the late ’60s, residents of Point Pleasant, West Virginia, had reported encountering a bizarre winged creature—just before scores died in a fatal bridge collapse. The film combines the two, constructing a long-lasting legend out of an already frightening history in a small town.
3. Borderland (2007)
A spring break vacation becomes a battle to stay alive in this movie based on the life of Adolfo de Jesús Constanzo, a cult leader and narcotics trafficker who believed in ritual sacrifice. The actual slaying of a college student named Mark Kilroy was an international news shocker, and the film doesn’t pull any punches when it comes to gore.
2. The Girl Next Door (2007)
Few tales are more chilling than the actual torture and killing of Sylvia Likens by her caretaker and local children. This gruesome film version removes supernatural shocks and serves up something much more frightening: brutality that occurred.
1. Them (Ils) (2006)
Human monsters are often the most frightening. The film is based on a real-life killing of an Austrian couple in the Czech Republic, but whether or not the facts in the film are true. Either way, it reaches down to our innermost fear, hunted for no reason whatsoever.
Horror strikes more when it gets fuzzy between fact and fiction. They remind us that even if ghosts, monsters, and killers have their place on the screen, the most frightening tales usually arise from reality.