Experts and investigators explore the crimes and backgrounds of serial killers who work in pairs. They look into the psychology of Fred and Rosemary West and others.

Experts examine the backgrounds of some of history's most notorious serial killers. They explore the crimes and psychology of Peter Sutcliffe and Jeffrey Dahmer.

Experts and investigators examine the backgrounds of the world's most notorious serial killers to create a cognitive psychological profile and find out what made them kill.

Experts examine the backgrounds of serial killers with sexual desires. How do so many of them evade capture and what leads them to commit these heinous crimes?