Fritz HaarmannKnown as: The Butcher of HanoverM.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, GermanyVictim count: convicted for 24, suspected of 27Info: 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 Zrtlichkeit der Wlfe 1973 and Der Totmacher based on Haarmann's crimes. However updated English language versions would be very welcome to those curious about true crime.

Gary RidgwayKnown as: The Green River KillerM.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, USAVictim count: 71 confessed, 90 suspectedInfo: 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.

Alexander PichushkinKnown as: The Chessboard KillerM.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, RussiaVictim count: 48 - 60Info: 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.'

Harold ShipmanKnown as: Doctor DeathM.O.: giving lethal doses of heroin to elderly patients, sometimes for financial gain.Active: 1975 - 1998, EnglandVictim count: 250Info: 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.

Dr Henry Howard HolmesKnown as: The Devil in the White CityM.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, USAVictim count: 27 confessed, 200 suspectedInfo: 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.

Albert FishKnown as: The Gray ManM.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, USAVictim count: 3 convicted, up to 100 suspectedInfo: 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 ChaseKnown as: The Vampire of SacramentoM.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, USAVictim count: 6Info: 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.