World's Most Evil Killers - Season 9

Examining the crimes of Glen McCurley, who in 1974 abducted 17-year-old Carla Walker from a bowling alley car park and killed her before leaving her body in a ditch.

An in-depth look at the life and crimes of William Devin Howell who was found guilty of the murders of seven different women.

An in-depth look at the life and crimes of Michael Bruce Ross who was executed in 2005 after raping and murdering women across Connecticut and New York.

A profile of serial killer Donald Henry Gaskins who stabbed, shot, drowned and poisoned more than a dozen people in South Carolina in the 1970s.

An in-depth look at the life and crimes of Wayne Williams who is serving life in prison for the murder of two men but suspected to be responsible for at least 24 other murders.

An in-depth look at the life and crimes of David Marmolejo, who was convicted of the murder of his own mother.

Examining the life and crimes of Emanuel Lovell Webb, known as the East End Killer, who raped and killed four women in Bridgeport, Connecticut between 1990 and 1993.

Westley Allan Dodd exterior concealed a man with sadistic urges. By the age of 28, he was responsible taking the lives of three young boys.

In 1993, police officers pulled over a young man for erratic driving. Within the car, they found the body of a murdered woman.

To some, nurse Charles Cullen was a friendly face, always willing to lend a hand. None suspected what he really was: a relentless and ruthless killer.