
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.

A serial killer brutally snatches away the lives of eight innocent women during a decade-long killing spree in Louisiana.

A killer murders her own son and becomes the first woman to be executed in Florida since 1848.

A terrifying killer snatches away the lives of four victims before being caught while trying to claim his fifth.

The I-95 killer, who brutally killed six men in 1994, is executed three years later.