15 terrifying horror films you (probably) didn't know were based on true stories

Alfred Hitchcock’s black-and-white classic is as timeless as its real-life origins are infamous. The story of Norman Bates (Anthony Perkins) and his “mother” issues is said to be inspired by the story of Ed Gein, a Wisconsin man who was convicted of murder in the 1950s but is suspected of having a much higher body count. On top of being a killer, Gein was an amateur grave robber prone to making unique home decor, including a lampshade composed of human skin from a person’s face.

Another Hitchcock classic, , is a nail-biting tale of a small town struggling to survive an invasion of avian attackers. The Birds novella—written by Daphne du Maurier—and Hitchcock’s film owe their origins to a 1961 event that briefly upended life in sleepy Santa Cruz, California.A local newspaper there documented a rare attack by a massive flock of seabirds; they littered the streets and front lawns after colliding with buildings and swarming citizens. The story goes that, three days after reading the article, Hitchcock phoned the paper to tell them that he would be using the piece as research for the terror he was about to inflict on Bodega Bay—a real town north of Santa Cruz that, luckily, hasn’t actually ever been attacked by avians.

Quite possibly the most terrifying horror film ever made (and certainly one of the best), becomes even scarier when you consider its story about a young Washington, D.C. girl possessed by a demon is closer to truth than fiction., who wrote both the Oscar-winning screenplay and the bestselling 1971 novel, was first inspired by a 14-year-old boy’s exorcism that reportedly occurred in 1949. While attending Georgetown University, Blatty became fascinated with the boy’s case as documented in The Washington Post story “Priest Frees Mt. Rainier Boy Reported Held in Devil’s Grip.”Like Regan (Linda Blair) in the movie, the boy her character is based on also played with a Ouija Board. Ultimately, two priests—like in the film—performed the rite of exorcism to save the boy’s soul. Unlike Regan, however, who only needed one exorcism, the boy required the ritual to be performed 20 to 30 times.

Fans of Steven Spielberg’s legendary blockbuster, and Peter Benchley’s novel of the same name, know that is based (in part) on a very bloody true story. But not the one fans usually think of.The film—which centers on a great white shark terrorizing a New England beach town—owes most of its game-changing legacy not to the 1916 shark attack on the Jersey shore that is mostly associated with it, but rather a more obscure incident from 1964. In his book’s introduction, Benchley writes that he came up with Jaws upon reading an article about fisherman Frank Mundus and his frightening encounter with a 4,500-pound great white off the shores of Long Island. Benchley used Mundus as inspiration for the character of shark hunter Quint, played famously by Robert Shaw. But unlike Quint, Mundus did not get turned into chum when squaring off with the shark. Instead, he harpooned the shark, Old Man And The Sea-style, and dragged it out of the ocean.

Arguably the horror film based on the most widely-known real events, has spent more than four decades giving audiences a permanent case of night terrors with its story of a young couple terrorized by violent spirts at their house in Amityville, New York. In 1975, four years before Amityville’s release, the real-life Lutz family claimed to have suffered a fate similar to that of their fictional counterparts.After moving into their home—one year after its previous occupant, Ronald DeFeo Jr., murdered six of his family members there—the Lutz family reported hearing strange sounds and seeing even stranger sights. The unexplained events built in intensity and frequency, forcing the family to flee from their supposedly haunted house. But, in the years since their story made headlines, the Lutz’s infamous claims have been debunked. All of their reports of seeing black ooze and ectoplasm in their home were, yup, false. As were their claims of seeing cloven hoofprints in the snow around their property—because, at the time they made their report, there was no snow on the ground. But leave it to Hollywood to not let something like the truth get in the way of telling a great story.

In , directed by Tobe Hooper and produced by Steven Spielberg (and, somehow, rated PG), the Freeling family struggles to survive a paranormal assault when they discover that their home is built on a haunted burial ground. While Poltergeist takes place in suburban California, the haunting that supposedly inspired the film originated 3,000 miles away in New York state.In 1958, in the town of Seaford, the Hermann family claimed to be victims of paranormal activities that would be immortalized in one of the most popular films of the 1980s. They allegedly saw bottle tops pop off on their own, along with those bottles seemingly moved by an invisible hand. Their claims went viral and dominated local and national news cycles, to the point where did a piece on it. Like the Freelings, the Hermanns also invited paranormal experts into their home to help deal with their very unique ghost problem. While these researchers were able to record some evidence of strange events, the occurrences mysteriously stopped shortly after the team arrived. Thankfully, whatever the Hermanns think they saw, it stayed around long enough to inspire one of the best horror films of the ’80s.

director Wes Craven told in an oral history that the idea of teens being stalked in their sleep by Freddy Krueger came after the late filmmaker read an article in the Los Angeles Times about a Cambodian family whose young son struggled with vivid night terrors.The late filmmaker revealed: “[The boy] told his parents he was afraid that if he slept, the thing chasing him would get him. So he tried to stay awake for days at a time.” Like most of the teens in Elm Street, this young boy sadly died in his sleep, likely the victim of rather than of a ghoul wearing a glove with knives for fingers.

While not as popular or commercially successful as A Nightmare On Elm Street, Craven’s underrated used frightening real-life stories to inspire its equally frightening fictional one.The 1988 film is based on the book of the same name by Harvard Ph.D. Wade Davis. The compelling book centers on the case of a man who had “been a zombie” for two years and was allegedly poisoned, buried alive, and revived with an herbal brew. Dr. Davis journeyed to Haiti in search of the drug used in zombification rituals. Craven’s loose adaptation of Davis’ experiences takes many generous, R-rated liberties, but it does remain faithful to the source material’s chilling chronicle of humanity’s universal fear of being buried alive.

The only horror movie to win the Best Picture Oscar,  made Hannibal “The Cannibal” Lecter a chilling household name, while putting Thomas Harris’ bestseller and the true crime cases that inspired it into the national spotlight.Ted Tally’s Oscar-nominated script, based on Harris’ book, used an amalgam of real-life FBI investigations to create serial killer Buffalo Bill. Ted Bundy, like Bill, faked injuries to bait his victims. And, like Lecter, Bundy also aided in creating a criminal profile to help catch the prolific Green River Killer. As for Bill’s infamous torture pit in the bowels of his home? That aspect of Agent Clarice Starling’s prey is tied to Philadelphia serial killer Gary Heidnik, who murdered and tortured six victims in his basement.

Rob Reiner is responsible for two of the greatest Stephen King adaptations: Stand By Me (based on King’s short story “The Body”) and the Oscar-winning . The latter is based, in part, on King’s real-life experiences following the release of his fantasy novel, The Eyes Of The Dragon. The negative backlash he received from fans was so strong, that King used it as inspiration when writing the tale of popular author Paul Sheldon (James Caan) and his harrowing attempts to escape crazed fan, Annie Wilkes (eventual Oscar-winner Kathy Bates).The fanatical Wilkes—and her gruesome, violent ways—stem from the inner demons that plagued her creator. In 2006, King told that Annie was a metaphor for the author’s drug addiction. “She was my number one fan” and “she never wanted to leave.”

, Wes Craven’s meta slasher film, became a sleeper hit at the 1996 Christmas box office and a defining milestone for the genre. In the film, teenager Sydney Prescott (Neve Campbell) and her friends struggle to evade the Ghostface killer before his knife finds them. The only things more unsettling about Scream’s murder mystery plot are the murders that the filmmakers say inspired it.On Scream’s 20th anniversary in 2016, ran a riveting piece that chronicled the horrific crimes in Florida that served as a foundation for those that transpired in Scream’s fictional town of Woodsboro. In August 1990, Danny Rolling would be christened “The Gainesville Ripper” after he, like Ghostface, used a knife to kill five students in Florida. Scream writer Kevin Williamson was housesitting in Los Angeles, watching TV, when a special about the Gainesville murders aired.According to Complex, Williamson said it freaked him out so bad that he imagined a knife-wielding killer stalking him outside the home he was in. Those “so-not-sleeping-tonight” thoughts inspired , and paved the way for one of the most popular horror franchises in movie history.

A notorious box office failure upon its initial release, has since developed a small-but-loyal cult following—thanks in part to this historical horror movie’s real-life inspirations.Disturbing and bloody barely covers Ravenous’ take on “Colorado Cannibal” Alfred Packer. In 1874, a somewhat deranged Packer confessed to murdering and (gulp) eating his fellow travelers as they struggled to traverse Colorado’s San Juan mountains during a (no pun intended) deadly winter.

Before he made Aquaman, director James Wan earned his bonafides with horror fans with , a modern classic of the genre. The Warrens, married paranormal investigators played by Patrick Wilson and Vera Farmiga, are based on real people who claim to have encountered and battled real supernatural threats. The actual Lorraine Warren was a consultant on the movie and insists that the haunting that plagues the fictional family and their home in the movie really happened. “Whoever the spirit was,” Warren told , “she perceived herself to be mistress of the house, and she resented the competition my mother posed for that position.”