Horror movies shock, sicken and terrify us, but real life provides an insane amount of gruesome material.
These guys are so horribly deranged that they're screaming out for their depraved stories to be documented in equally depraved movies...
1. Fritz Haarmann
Known as: The Butcher of Hanover
M.O.: he would lure boys and young men to his home, where he would sexually penetrate them and bite their necks open, often simultaneously.
Active: 1918 - 1924, Germany
Victim count: convicted for 24, suspected of 27
Info: Haarmann and his accomplice, Hans Grans, would butcher victims' bodies and sell the meat on the black market. Haarman evaded capture for years, despite working closely with the police as an informant!
Note: There were actually a couple of German movies, Die Zärtlichkeit der Wölfe (1973) and Der Totmacher based on Haarmann's crimes. However updated English language versions would be very welcome to those curious about true crime.
2. Gary Ridgway
Known as: The Green River Killer
M.O.: Luring prostitutes and runaways into his truck, using a picture of his son to gain trust. He then strangled them and had intercourse with their bodies.
Active: 1980 - ca. 1998 in Washington State, USA
Victim count: 71 confessed, 90+ suspected
Info: Police consulted infamous killer Ted Bundy for help in his arrest. Ridgway had a twisted version of religion, preaching 'Christian' gospel from door to door.
3. Alexander Pichushkin
Known as: The Chessboard Killer
M.O.: tempting vagrants into Moscow's Bitsa Park with vodka, he'd kill them with a hammer, then push the vodka bottle into their skulls.
Active: 1992 - 2006, Moscow, Russia
Victim count: 48 - 60
Info: Pichushkin had the bizarre ambition to kill 64 people - the number of squares on a chessboard. He said of his first murder, 'A first killing is like your first love. You never forget it.'
4. Harold Shipman
Known as: Doctor Death
M.O.: giving lethal doses of heroin to elderly patients, sometimes for financial gain.
Active: 1975 - 1998, England
Victim count: 250+
Info: Although Shipman mostly targeted older patients, his youngest victim was only 41. Shipman, who hanged himself in his cell after receiving a life sentence, is the only British doctor to have been found guilty of killing his patients.
5. Dr Henry Howard Holmes
Known as: The Devil in the White City
M.O.: trapping guests and staff in his 'murder mansion' - a hotel full of hidden passageways and trick doors - where they were suffocated or gassed in secret chambers.
Active: 1888 - 1894, Chicago, USA
Victim count: 27 confessed, 200+ suspected
Info: Holmes not only cashed in on life insurance policies of his victims, but cleaned and sold some of the bodies to medical schools. Sweeney Todd style, Holmes used a secret chute to transport bodies from the kill site to his basement.
Known as: The Gray Man
M.O.: He would trick children into his house before choking them and horribly mutilating the bodies. His extensive confessions give lurid descriptions of his depravity.
Active: 1924 - 1932, New York, USA
Victim count: 3 convicted, up to 100 suspected
Info: Fish was possibly the most brutal and crazed killer ever. A paedophile and religious maniac, he tortured, dismembered and ate his child victims. He would also insert needles and burning fabric into his own groin and orifices for sexual pleasure.
Richard Trenton Chase
Known as: The Vampire of Sacramento
M.O.: he shot his victims, then sometimes had sex with their corpses before drinking and bathing in their blood and cannibalising the bodies.
Active: 1977 - 1978, California, USA
Victim count: 6
Info: Chase was major-league crazy. He believed he needed to drink human blood to stop Nazis from using poison hidden under his soap dish to change his blood into powder. In prison, other inmates feared and hated him and would frequently urge him to kill himself, which he finally did in 1980.
These reprehensible criminals have not yet had their stories shared with the public on the big screen. Remember - what these people did is unforgivable, but drawing on real life keeps horror movies...horrifying.