The 'Killer Clown' who kept bodies of young men and boys buried under his Chicago home.

Targeted his patients, the majority of whom were elderly women. Killed his patients with lethal injections of diamorphine.

Testimony gained under torture and confession under threat of torture, as was customary

Targeted young boys. Arrested in 1999.

Born 1765, died 1840. Leader of the Thuggee cult.

Killed young and poor children from all across Pakistan along with three teenage accomplices. Surrendered himself to the police after his 100th kill, but committed suicide before being executed.

Accused of murdering 600 or so people, however no public trial was held. Was imprisoned in a room of her own castle until her death.

Convicted and sentenced to 128 years, but the maximum one can serve in Brazil is 30 years. He claimed to have killed over 100 victims, 40 of them inmates.

Convicted on 15 counts of murder, but left a cryptic list of 65 murders. May have had an accomplice.

Would enter victim's homes at night and kill everyone with axes, meat cleavers, hammers and shovels.

Targeted young girls. Arrested in 1980.

Convicted of the murder of 52 women and children between 1978 and 1990. 3 people were previously convicted and executed for his crimes

Convicted of the murders of 9 people in 1989, and 43 people in 1995–1996. Traveled through Europe illegally from 1990–1995; whether he killed during this time is unknown.

Preyed on unemployed women: Posed as a businessman and lured his victims with the prospects of a job, leading them to an isolated place, then raped, tortured and murdered them.

Estimated that he may have killed more than 100 people.