This episode deals with Jesse Matthew, guilty of the murders of Morgan Harrington and Hannah Graham.

The documentary looks at Stephen Port, who preyed on young men and spent hours searching web porn. The predator took the lives of four much-loved men.

The programme delves into the crimes of William Devin Howell, who murdered opioid-addicted prostitutes and kept the killings secret for 14 years.

A profile of murderer James Fairweather, who stabbed two people to death in Essex in the space of three months in 2014.

The crimes of Mark Martin, who idolised serial killers before becoming one himself. Martin killed three homeless women in Nottingham between December 2004 and January 2005.

A profile of Shawn Grate, who was given the death penalty in June 2018 after being convicted of two murders in Ashland County, Ohio.