World's Most Evil Killers

The Grindr Killer, Stephen Port, murdered at least four men from gay social networks.

In 2012, April Jones disappeared from outside her home in Wales, never to be seen again; her abductor and murderer is Mark Bridger.

In 2012, fame-hungry Mick Philpott killed six of his own children by setting fire to the family home.

In 2010, bodybuilder Raoul Moat shot his ex-girlfriend and her partner and went on the run.

For one week in 2016, Stefano Brizzi stored the body of a policeman in his apartment in London.

On July 1st, 2000, eight-year-old Sarah Payne was snatched from the street in Littlehampton, West Sussex.

On December 1st, 1996, Tracie Andrews had stabbed her own fiancé Lee Harvey to death.

Dorothea Puente was a convicted serial killer who ran a boarding house in the 1980s; she cashed in the Social Security checks of the elderly and disabled boarders living in her house; many of them ended up dead and buried in the backyard.

Rodney Alcala, who once appeared as a contestant on "The Dating Game," is sentenced to death over five murders committed in the '70s and later confesses to 30 more, but is believed to have killed up to 130 people.

Born in El Paso, Texas, on February 29, 1960, Richard Ramirez was an American serial killer who over a two-year rampage raped and tortured more than 25 victims and murdered more than a dozen, most of them in their own homes.

Charles Ng Chi-Tat is a serial killer; he is believed to have raped, tortured and murdered between 11 and 25 victims with his accomplice Leonard Lake at Lake's cabin in Calaveras County, Calif. Between 1983-1985.

The Sunderland Strangler, Steven Grieveson, killed four teenage boys in the early 90s.

Railway Killers John Duffy and David Mulcahy killed three women and raped many more.

Cary Stayner is a serial killer who murdered four women at Yosemite National Park and was the product of a uniquely tragic background; in 1972, Stayner's brother, Steven, was abducted by child molester Kenneth Parnell but Steven escaped.

Serial killer Edmund Kemper killed six young women in the Santa Cruz, Calif. area and several members of his family; at the age of 15, he killed both his grandparents to see what it felt like.

The disturbing and horrifying case of Horst Kroener, a 53-year-old German man who was jailed in 2016 for brutally murdering his wife when she was asleep in their bed.

From October 1989 to April 1991, Wolfgang Schmidt murders five women and an infant; the area where some of the crimes take place leads to a second moniker, "the Beast of Beelitz."

A look at serial killer Jack Unterweger.

Danilo Restivo, originally from Italy, was jailed for murdering and mutilating his Bournemouth neighbor, Heather Barnett, in 2002.

An examination of the Polish serial killer who came to be known as The Scorpion.