Horror movies that are based on true stories are particularly spine tingling because there is that little voice in the back of your head telling you, "wait, that actually happened?!" In turn, any coping mechanisms to quell the unease in one's stomach - which relies on self talk that it's "just a story" - is ratcheted up that much more.
Whether it's haunted houses hiding in plain sight, or people literally dying from their nightmares, here are the 10 best horror movies that are based on true stories.
The Amityville Horror
Moving into a new house can be satisfying on a number of levels. For some, it can mark the transition from apartment living to something more substantial. For others, it can mark the start of having a family of their own. However, no one really knows who or what took place inside those walls.
In The Amityville Horror, a family of five, the Lutzes, moves into a suburban neighborhood on the south shore of Long Island, New York and begins to experience the terrifying repercussions that stem from the past occupants who were all brutally murdered by their son/sibling. It's particularly unsettling because the film evokes all the senses - whether that's the sound of buzzing insects, the faint smell of perfume or the weight of a presence in a seemingly unoccupied room.
The film is based on a book of the same name which depicts the true actions of Ronald J. DeFeo Jr. who murdered his entire family in cold blood on November 13, 1974.
Much like in the film, the Lutz family were so off-put by what they experienced, they moved out of the house after only 28 days - leaving in such a hurry that they didn't even bother to pack up their clothes.
David Cronenberg's film, Dead Ringers, finds Jeremy Irons playing identical twin gynecologists, Elliot and Beverly Mantle, who run a successful medical practice in Toronto. Although their personalities differ, the Mantle twins use their shared physical traits to pawn female companions onto one other.
When Beverly begins to have a psychotic break - interpreting his female patients as mutant-like creatures - he charts a course to physically deform them with archaic gynecological tools. After injuring a patient, the practice faces irreparable harm and both brothers fall deeper into psychosis.
Based on the true story of Stewart and Cyril Marcus - twin gynecologists on staff at New York Hospital-Cornell Medical Center - their seemingly perfect lives began unraveling as those around them saw their mental faculties beginning to erode.
Although the film takes several creative liberties, issues relating to depression, drug dependency, a shared sense of self, and a shocking ending for once-esteemed medical professionals all come from the Marcus's bizarre lives.
Open Water is a prominent example that a horror film doesn't have to pit helpless individuals against crazed and masked figures. Rather, often the scariest situations involve being a victim of circumstance.
What starts out as a sun-filled day scuba diving in the crystal blue waters of the Bahamas, suddenly turns harrowing when a couple is left behind and forced to reckon with the inevitabilities of the darkening sky - as well as what is lurking beneath them.
Based on the true story of Tom and Eileen Lonergan - who were left behind during a scuba expedition along the Great Barrier Reef - the couple were left adrift for two days before anyone from the fishing vessel knew that they had unaccounted for passengers.
Many people's gripes with horror films is the logic behind the actions of those being tormented. However, that is easily dealt with in The Conjuring - as the film centers on the exploits of Ed and Lorraine Warren - who as paranormal researchers actively seek out disturbing settings (like the aforementioned Amityville Horror house).
The Warrens's focus is the Perron family who know something is amiss with their new home. While it's certainly a classic set-up, the film delivers a number of shocking jolts that will leave you pining for a reprieve from the visual onslaught.
The scenario - and both the Warrens and Perron families - are based on the true relationship forged between the paranormal experts and the impacted family.
The Warrens themselves have come under criticism from naysayers who charge them with inventing ghost stories, although the Perron family has backed up their claims as it relates to The Conjuring.
The Perron's oldest daughter, Andrea, commented, "Both my mother and I would just as soon swallow our tongue than tell a lie. People are free to believe whatever they want to believe. But I know what we experienced."
The Exorcism of Emily Rose
The Exorcism of Emily Rose is an inventive take on what it means to not only experience what demonic possession is like, but also the consequences that stem from exhausting every possible means of curing an ailing 19-year-old girl. In this case, when an exorcism goes wrong, it opens up all the moral and legal issues that don't fit into a tidy courtroom box.
Like in the cases involving paranormal researchers, Ed and Lorraine Warren, most people are skeptical when it comes to anything supernatural. Thus, the task for the lawyer of the condemned priest who botched the exorcism must first prove that demonic possession is real in order to get a not-guilty verdict.
The film is based upon the life and death of Anneliese Michel who grew up in Post-World War II Germany and began suffering from symptoms that today would be diagnosed as schizophrenia.
However, her devoutly Catholic family insisted it was the devil's handiwork and pressed that their local parish perform an exorcism.
Under the direction of Father Arnold Renz, Anneliese was severely deprived of food and water and physically abused - under the guise that he was actually helping her.
After she was found head, her parents, Renz, and another priest, Ernst Alt, were all found guilty and liable for her death.
Australian film, Wolf Creek, eschews any elevated set-pieces or unrealistic motivations for the antagonist in favor of an ultra realistic depiction of a road trip gone wrong.
When three friends find themselves stranded near Wolf Creek National Park in Western Australia, the group is approached by a would-be good samaritan who offers to tow them to his nearby house where he has the tools and resources to help him,.
While on paper it may seem naive, the circumstances are such that the help is really the only lifeline that the weary travelers can hang on to - and would be similar to the couple bobbing in the water in Open Water to refuse a boat driven by a stranger.
What ensues is one of the most violent and disturbing displays of violence in cinematic history - causing a rift amongst the film community who saw it as either a misogynistic trash heap, or a barrier-breaking look at violence without a cartoon lens.
As the title card for the film suggests, "it is based on true events" and is an amalgamation of the murderous exploits of convicted killers, Bradley John Murdoch and Ivan Milat - the latter who was nicknamed "the backpack killer" after killing seven travelers along Belanglo State Forest between Sydney and Canberra.
The Exorcist remains one of the most highly-influential and important films for a generation of filmmakers - from a variety of different genres - who were all impacted by the afflictions of a once sweet little girl who slowly morphed into a bile spewing monster.
Perhaps it's because director, William Friedkin, never set out to make a horror film. Rather, his motivations stemmed from a desire to explore "the mystery of faith" which created a story that sought greater underlying meaning than other films lumped into the genre.
The film and book in which it is based stems from the real afflictions of Roland Doe, a pseudonym given to the victim by the Catholic Church in the 1940s, who was determined to have been possessed by an evil spirit who was responsible for unexplained occurrences in Doe's house and physical wounds to both himself and those around him.
Over 30 exorcism ceremonies took place over the course of several weeks - relying on 9 different priests and 39 other witnesses who all signed the final ecclesiastical papers which concluded that Doe had been cured on his possession.
A Nightmare on Elm Street
It simply wasn't enough for Wes Craven to torment people all around the world with monsters that attack a person while they go about their daily lives - like in The Hills Have Eyes or Swamp Thing. Instead, he conjured up a villain, Freddy Kruger, who would exact his revenge during a period when everyone - regardless of physical power - is at their most vulnerable; when they are asleep.
Craven drew inspiration from a Cambodian family who fled the Killing Fields and immigrated to the United Stats. However, the son couldn't escape his harrowing past and often had debilitating nightmares.
"He 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, Craven said. "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. Here was a youngster having a vision of a horror that everyone older was denying. That became the central line of Nightmare on Elm Street."
The Los Angeles Times article which served as the original source material noted that 104 men - with an average age of 33 - had mysteriously died in their sleep.
The Hills Have Eyes
The thematic premise of a "trip gone bad" remains a tried-and-true set-up for a variety of horror film. Wes Craven's The Hills Have Eyes in no different; a large family is headed from Ohio to Los Angeles when car trouble derails their progress and forces them to deal with another family in the area who has an insatiable hunger for human flesh.
Craven's film was inspired by the story of the Sawney Beane family who he had read about in the New York Public Library.
"In the 1700s in Scotland I believe, there was an area that had road running through it from Scotland, and people thought it was haunted because people kept disappearing from that road," he said. "The story came out when a couple was attacked by these wild looking people, and one got away."
According to the BBC, the Bean clan supposedly killed and ate 1,000 people over the course of 25-years."
The Haunting in Connecticut
The Haunting in Connecticut is an inventive take on the haunted house horror genre. By adding a sick child riddled with cancer into the equation, a family needs to make their new home work out of sheer proximity to the hospital.
But of course, there are secrets lurking which involved the original purpose of the house - as a mortuary - and the spirits contained inside of the walls.
The film is based on the recall of the Snedeker family of Southington, Connecticut from 1986 who hired Ed and Lorraine Warren who contended that mortuary staff had practice necromancy and necrophilia with the corpses.