Season 1 of World's Most Evil Killers premiered on March 11, 2018.

World’s Most Evil Killers delves into the gripping real-life stories of the world’s most terrifying and prolific killers. From Fred and Rose West to Ed Gein – The Clown Killer – and even to The Milwaukee Cannibal. Each episode focuses on one notorious killer and features authentic first-hand accounts of their behavior, from detectives who ran the case, journalists who reported on the stories, relatives, and at times survivors, alongside series experts who provide analysis. These criminologists, crime journalists and psychologists examine how the infamous killers made headlines both nationally and internationally and why they still continue to evoke fear and fascination in the public eye.

Season 2 of World's Most Evil Killers premiered on May 6, 2018.

World’s Most Evil Killers delves into the gripping real-life stories of the world’s most terrifying and prolific killers. From Fred and Rose West to Ed Gein – The Clown Killer – and even to The Milwaukee Cannibal. Each episode focuses on one notorious killer and features authentic first-hand accounts of their behavior, from detectives who ran the case, journalists who reported on the stories, relatives, and at times survivors, alongside series experts who provide analysis. These criminologists, crime journalists and psychologists examine how the infamous killers made headlines both nationally and internationally and why they still continue to evoke fear and fascination in the public eye.

Season 3 of World's Most Evil Killers premiered on April 28, 2019.

An in-depth look at the lives and crimes of some of the World's most evil killers.

Season 4 of World's Most Evil Killers premiered on May 26, 2020.

An in-depth look at the lives and crimes of some of the World's most evil killers.

Season 5 of World's Most Evil Killers premiered on January 19, 2021.

An in-depth look at the lives and crimes of some of the World's most evil killers.

Season 6 of World's Most Evil Killers premiered on October 19, 2021.

An in-depth look at the lives and crimes of some of the World's most evil killers.

Season 7 of World's Most Evil Killers premiered on November 22, 2022.

An in-depth look at the lives and crimes of some of the World's most evil killers.

Season 8 of World's Most Evil Killers premiered on November 23, 2023.

An in-depth look at the lives and crimes of some of the World's most evil killers.