You know how when you are watching a gut-wrenching horror movie, you try to rationalize by silently repeating, “It’s just a movie.”

Well, not to add to your horror-movie-induced anxiety attacks, but this mantra is not always applicable. Many hair-raising films are actually based on real-life events.

From knife-wielding serial killers to haunted dolls, the following 20 horror movies were inspired by true events.

Note: After reading this article, you might feel the urge to take a bath in holy water. Do that!

The Movie: Considered goofy by today’s bone-chilling horror movie standards, Hitchcock’s 1963 film, “The Birds,” was one of the scariest films at the time. Starring Tippi Hedren, the movie centers on a small coastal town terrorized by a flock of hostile birds.

What really happened:  On Aug. 18, 1961, the residents of the seaside town of Capitola in California awoke to a scene straight out of a horror film. Flocks of angered seabirds turned against local humans, dive bombing their homes, crashing into cars and vomiting half-digested anchovies onto their yards. It was a complete mystery at the time, and it took scientists years to discover that the normally mild-tempered birds were poisoned by toxic algae, which was the reason behind their bizarre behavior.

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The Movie: This dark, 1971 masterpiece featuring a spine-tingling lead performance from Richard Attenborough remains an underrated crime gem. The British crime drama tells the story of serial killer John Christie.

What really happened: John Christie is one of London’s most infamous serial killers and alleged necrophiliac who, in the 1940s and ’50s, killed at least eight women—including his wife Ethel—and hid their bodies in the walls of his flat at 10 Rillington Place, Notting Hill, London.

The Movie: The harrowing 1973 tale of a pre-teen girl possessed by an inexplicable sinister force continues to shock audiences years after its debut. The film is based on a 1971 horror novel of the same name by William Peter Blatty.

What really happened: In the late 1940s, 13-year-old Roland Doe started behaving strangely. Doe’s aunt (who had taught him about spiritualism and how to use a Ouija board) died right around the time these bizarre things began happening. Several priests were summoned to perform exorcisms on the pre-teen, who reportedly spoke in Latin and had scratch marks on his body. One of the exorcism sessions was reportedly stopped when Doe threw a mattress spring at the priest. There is still no explanation for what happened to Doe.

The Movie: The 1974 horror classic, beloved by cinephiles with a taste for macabre tales, centers on chainsaw murderer “Leatherface” and his psychopathic family who torment and kill a group of teenagers.

What really happened: The gory film is loosely based on the real-life serial killer Ed Gein, also dubbed “the Butcher of Plainfield.” During the ’50s, Gein exhumed dead bodies and made keepsakes from their bones.

The Movie: A leftfield success during the horror boom of the late 1970s, this grotesque haunted house tale is inspired by Jay Anson’s book “The Amityville Horror” based on the real-life paranormal claims.

What really happened: In 1974, Ronald DeFeo, Jr., shot and killed six members of his family in their Amityville, N.Y., home at 112 Ocean Avenue. One year later, the Lutz family moved into that same house but moved out after only a month. During the 28 days the family spent in the house, they reportedly experienced all sorts of grim paranormal events, as portrayed in the film.

The Movie: The 1982 haunted house classic is still terrifying even after 40 years. The movie, co-written by Steven Spielberg, centers on a family whose home was built on a burial site and terrorized by demonic spirits.

What really happened: The movie’s plot was inspired by the mysterious events that happened at the Hermann family’s Long Island home in 1958. The Hermanns claimed their home was haunted by a poltergeist, and that household objects would fly around mysteriously. Eventually, the family moved, believing the events were related to a Native American burial ground near the house.

The Movie: Wes Craven’s slasher hit tells the story of a twisted killer “Freddy Kruger” who hunts teenagers in their sleep. More chilling than the premise is the fact the film was inspired by newspaper articles published by The Los Angeles Times in the late ’70s about South Asian men who were dying in their sleep.

What really happened: In the 1970s, a number of Southeast Asian refugees who had fled to the United States from war-torn countries died in their sleep. One young boy, whose family had survived the killing fields of Cambodia, had terrible nightmares of something chasing him in his sleep. “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,” director Wes Craven told Cinemablend in 2014. “When he finally fell asleep, his parents thought this crisis was over. Then they heard screams in the middle of the night. By the time they got to him, he was dead. He died in the middle of a nightmare.”

The movie: David Cronenberg’s intense psychological drama is an emotionally draining study of the twisted relationship between identical twin gynecologists Beverly and Elliot Mantle.

What really happened: Elements of the 1988 movie were based on the stranger-than-fiction, real-life story of identical twin gynecologists Cyril and Marcus Stewart. The brothers who had died from barbiturate withdrawal were discovered partially naked and almost decayed in their New York apartment in 1975.

The movie: The iconic slasher flick that would spawn a franchise tells the story of the sleepy little town of Woodsboro, terrorized by a knife-wielding killer, “Ghostface,” who commits a string of gory slayings. Surprisingly enough, the 1996 horror classic starring Courtney Cox, Drew Barrymore, David Arquette, and Neve Campbell was actually based on a true story.

What really happened: In the early 1990s, Danny Rolling, known as the “Gainesville Ripper,” went on a killing spree in the student town of Gainesville, Florida. Claiming he wanted to be the next Ted Bundy, Rolling killed, raped, and mutilated five students. He pleaded guilty and was sentenced to death in 1994.

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The movie: The 1993 sci-fi movie is based on a book about a purported abduction titled “The Walton Experience.”

What really happened: Travis Walton, a forestry worker, claimed to have been abducted by aliens on Nov. 5, 1975, while heading home to Snowflake, Arizona. Walton was missing for five days before sharing his story.

The movie: The 2002 biopic starring Jeremy Renner retells the story of a deranged serial killer Jeffrey Dahmer. The independent film features a mix of present-day and flashbacks to Dahmer’s childhood, as well as his troubled relationship with his father.

What really happened: Jeffrey Dahmer, known as the “Milwaukee Cannibal,” was responsible for the death of 17 boys and young men from the 1970s through early 1991. Dahmer mutilated, preserved, and partially consumed the bodies of his victims. The chilling story  is also adapted in the 2017 film “My Friend Dahmer” and the 2022 Netflix series “Dahmer – Monster: The Jeffrey Dahmer Story.”

The movie: A searing portrayal of a prostitute-turned-serial killer in the 2003 crime drama “Monster” earned Charlize Theron 17 awards, including an Oscar.

What really happened: Allien Wuornos was a Florida prostitute who, between 1989 and 1990, shot dead and robbed seven of her clients.

The movie: The 2003 survival horror flick that will most likely give you thalassophobia (fear of the ocean) follows the nightmarish story of American tourists who are accidentally left behind by a tour group in shark-infested waters. The film was shot in the actual ocean with actual live sharks, making it more of a realistic nightmare than a full-fledged film.

What really happened: In January 1998, American tourists Tom and Eileen Lonergan were left behind on a group scuba diving trip off Australia’s Great Barrier Reef. Their bodies were never recovered.

The movie: The 2005 legal horror film featuring Jenifer Carpenter tells the story of a young woman who dies during an exorcism. The intelligent court drama with elements of demonic horror was based on the real-life story of a young German woman named Anneliese Michel.

What really happened:  In 1975, after Michel began experiencing hallucinations and seizures, her ultra-religious parents invited a couple of priests to perform exorcism rites on their daughter. The young woman died from malnutrition and dehydration. Her parents were charged with negligent homicide.

The movie: Greg McLean’s gut-wrenching slasher flick tells the tale of the deranged, tourist-hating serial killer Mick Taylor who haunts and kills backpackers in the Australian wilderness.

What really happened: During the late 1980s and early 1990s, Australian serial killer Ivan Milat hunted, assaulted, robbed, and killed multiple hitchhikers in southern New South Wales. Several bodies of missing young adults, ages 19 to 22, were found partly buried in Belanglo State Forest.

The movie: David Fincher’s 2007 nerve-shredding masterpiece follows Robert Graysmith (portrayed by Jake Gyllenhaal), a cartoonist who becomes obsessed with “the Zodiac Killer.”

What really happened: The movie is based on “the Zodiac Killer,” who terrorized San Francisco with a string of still-unsolved killings in the 1960s.

The movie: The 2007 horror flick will send shivers down the spine of every college student with upcoming spring break plans. The indie film follows a group of friends on a road trip to the Mexican border where they are met by a satanic cult looking for human sacrifices.

What really happened: This movie is loosely based on the life and crimes of American-born serial killer Adolfo Constanzo, who led an occult gang in Matamoros, Tamaulipas, Mexico. The cult committed several ritualistic killings in Matamoros, including the murder of Mark Kilroy, an American student abducted, tortured, and killed there in 1989.

The Movie: The ultra-successful horror franchise tells the story of demonologists Ed and Lorraine Warren (potrayed by Patrick Wilson and Vera Farmiga).

What really happened: The movie is based on the real-life paranormal investigators Ed and Lorraine Warren  and their account of supernatural activity at a farmhouse in Rhode Island in 1971.

The movie: The 2014 horror flick is a prequel to the 2013 “The Conjuring.” The movie tells the chilling tale of a vintage porcelain doll, Annabelle, cursed by a demonic spirit that causes violent ends to those who would wrong her.

What really happened: The premise of the horror flick was based on the allegedly haunted Raggedy Anne doll owned by Ed and Loraine Warren. Originally gifted to a nurse student in 1970, the doll is said to have been inhabited by the spirit of a dead girl named Annabelle and supposedly caused a great deal of demonic activity, as well as two near-death experiences and one fatal accident.

The movie: The 2018 film supernatural thriller stars Helen Mirren as heiress Sarah Winchester. The premise of the movie is based on the true story of the Winchester Mystery House.

What really happened: A historic landmark in San Jose, California, the Winchester House, was the residence of the late Sarah Winchester. In 1922, Sarah Winchester moved to San Jose after her infant daughter and husband passed away from childhood illnesses and tuberculosis. She renovated the eight-room farmhouse, and there were rumors of paranormal activity occurring at the house after it underwent renovations.

This article was produced and syndicated by MediaFeed.org.

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