World's Most Evil Killers

John Sweeney, also known as the Scalp Hunter, kills two of his former girlfriends and leaves their dismembered bodies in canals.

29-year-old Dale Cregan goes on a ruthless killing spree and murders four people.

Christopher Hightower is a killer con man who masquerades as a church leader and dupes people out of thousands of dollars; in 1991, Hightower slaughters a family of three after his friend Ernest Brendel lodges a complaint against him.

In the summer of 1976, David Richard Berkowitz, the Son of Sam, pleaded guilty to eight separate shootings that began in New York City.

Rapist Robert Napper sexually assaults and stabs Rachel Nickel nearly 50 times, and strikes again with another murder over a year later.

Sante and her son Kenneth Kimes are a murderous duo who killed three people in the 1990s; Sante Kimes fools victims across the U.S. during her outlandish 43-year crime spree.