
World's Most Evil Killers delves straight into the stories of the world's most prolific killers. Each episode focuses on one notorious killer and features first-hand accounts of their behavior; such killers range from Fred and Rose West, Ed Gein, the Clown Killer, to the Milwaukee Cannibal. Accounts are also given by detectives who ran the cases, journalists who reported on them, relatives, experts on analysis, and sometimes even survivors.

An examination of the Polish serial killer who came to be known as The Scorpion.

In 1999 and 2000, John Eric Armstrong cruised the streets of Detroit, Mich., looking for sex workers; seen as an ordinary husband, father and co-worker, no one in Armstrong's life suspected that he was a serial killer.

For nearly a decade, the Bayou Strangler deceived, bound, assaulted and murdered men, as he drifted across South Louisiana.

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."