Season 4

He was one of the biggest "celebrities" of the 1980's. His expensive suits and swagger earned him the nickname "Dapper Don". In reality, John Gotti was a man to be feared. He was a ruthless, dangerous Mafia gangster who ordered hits on his enemies, his friends and anyone who crossed him. In the 1970's, Gotti worked his way up the ranks of the Gambino crime family as a solid earner and vicious capo, determined to not let anything or anyone stand in his way. In 1985, he led the brutal murder of Mafia boss Paul Castellano and took the throne as the Gambino's Godfather, becoming public enemy #1. Law enforcement and other Goodfellas considered Gotti dangerous and unpredictable. For many years he seemed unstoppable. This installment explores how this common street thug became the ruler of one of the most powerful crime families in the world, and goes in-depth on the secret FBI operation that finally brought him down.

He was one of the biggest "celebrities" of the 1980's. His expensive suits and swagger earned him the nickname "Dapper Don". In reality, John Gotti was a man to be feared. He was a ruthless, dangerous Mafia gangster who ordered hits on his enemies, his friends and anyone who crossed him. In the 1970's, Gotti worked his way up the ranks of the Gambino crime family as a solid earner and vicious capo, determined to not let anything or anyone stand in his way. In 1985, he led the brutal murder of Mafia boss Paul Castellano and took the throne as the Gambino's Godfather, becoming public enemy #1. Law enforcement and other Goodfellas considered Gotti dangerous and unpredictable. For many years he seemed unstoppable. This installment explores how this common street thug became the ruler of one of the most powerful crime families in the world, and goes in-depth on the secret FBI operation that finally brought him down.

February 1, 2012: It was a normal night for Samantha Koenig, age 18. She was closing the Common Grounds Espresso coffee kiosk where she worked in Anchorage, Alaska, when one last customer, Isreal Keyes, age 34, stopped by. He was a man known in the community as a local business owner and caring father. But lurking beneath that harmless surface was a rapist and a ruthless killer with a penchant for selecting random victims throughout the country. Israel Keyes' kidnapping of Samantha Koenig led to an intense manhunt and a cross country investigation that ended his reign of terror. While in custody, Keyes played a cat-and-mouse game with detectives, revealing some details about his crimes and his missing victims. In the end, Keyes had one last surprise.

February 1, 2012: It was a normal night for Samantha Koenig, age 18. She was closing the Common Grounds Espresso coffee kiosk where she worked in Anchorage, Alaska, when one last customer, Isreal Keyes, age 34, stopped by. He was a man known in the community as a local business owner and caring father. But lurking beneath that harmless surface was a rapist and a ruthless killer with a penchant for selecting random victims throughout the country. Israel Keyes' kidnapping of Samantha Koenig led to an intense manhunt and a cross country investigation that ended his reign of terror. While in custody, Keyes played a cat-and-mouse game with detectives, revealing some details about his crimes and his missing victims. In the end, Keyes had one last surprise.

Serial rapists and killers Kenneth Bianchi and his cousin Angelo Buono Jr. (who was not Ken's blood relative) terrorize Los Angeles, California in the late 1970s, leaving a dozen or more women dead.

Serial rapists and killers Kenneth Bianchi and his cousin Angelo Buono Jr. (who was not Ken's blood relative) terrorize Los Angeles, California in the late 1970s, leaving a dozen or more women dead.

After his arrest, Sammy Gravano broke the oath of silence and cut a deal with the government, testifying against his former boss, John Gotti.

Sammy "The Bull" Gravano was one of the most feared mobsters in history he was the right-hand man to mafia kingpin John Gotti and carried out multiple murders on behalf of the crime family.

Clues point to Jesse Matthew Jr when women disappear in Charlottesville. Two women are killed, but one woman survives to bring the murderer to justice.

When college-aged women in Charlottesville start going missing, the search for answers leads authorities to local star athlete Jesse Matthew Jr.

A tip points to an unlikely suspect - a blonde, blue eyed accountant who lives with his wife in the suburbs.

From 1987-1992, Ontario authorities join the FBI's hunt for the monster responsible for s horrific crime spree.