
An in-depth look at some of the world's most dangerous murderers.

Keith Jesperson, known as the Happy Face Killer, brutally killed at least eight women across five American states in the early 1990s.

In 1999 and 2000, John Eric Armstrong cruises the streets of Detroit looking for sex workers.

The notorious story of a man convicted of the murder of two young girls, as well as another killing at a military base.

Four vicious murders put Mark Hobson at the center of a nationwide manhunt. Criminologists and psychologists try to decode this enigma.