
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.

The Baton Rouge Serial Killer, known for murdering seven women is sentenced to death for his chilling crimes.

The first woman executed by lethal injection after taking six lives.

A cold-blooded serial killer takes the lives of eleven people during a terrifying decade-long murder campaign.

A serial killer works as a nurse in Texas, where she kills many children and infants by injecting them with drugs.