A look at the criminal profile of Marc Dutroux, a Belgian serial killer who was convicted for kidnapping, torturing, and sexually abusing six victims until getting arrested in 1996.
An investigation into Mick Philpott, the notorious Derby father of 17 who murdered six children, five of them his own, when he set his own home on fire.
After Tracie Andrews' fiancé, Lee Harvey, is murdered in an apparent road-rage incident, she gives a heart-wrenching press conference, appealing to the public to help find her partner's killer.
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.
Serial killing partners Leonard Lake and Charles Ng murdered eleven people in California in the 1980s; they had a secret bunker where they raped and killed their prey.
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 murdered five women and an infant; the area where some of the crimes took place leads to a second moniker, "the Beast of Beelitz."