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

Christopher Halliwell's found guilty of murdering two women.

Dennis Rader, known to the world as the BTK Killer, killed ten people, including young children, between 1974 and 1991 in Wichita, Kansas.

Serial killer Bob Berdella, aka the Kansas City Butcher, kidnaps, rapes, tortures, and murders at least six men between 1984 and 1987 in Kansas City, Mo., forcing his victims to endure periods of up to six weeks of captivity.

On the surface, Zahid Zaman portrayed himself as a pillar of the community, but the true story of this cult killer was deeply sinister.