World's Most Evil Killers säsong 6

In 2002, police investigators had to rely on forensic analysis of text messages from the phone of missing Danielle Jones to convict Stuart Campbell of the murder of his 15-year-old niece.

The story of Harry Dhillon, who once attacked an ex-girlfriend in a jealous frenzy before brutally murdering Alice Ruggles after a campaign of harassment following the end of their relationship.

The story of 23-year-old killer Jamie Reynolds, whose fascination with extreme violence culminated in the harrowing murder of 17-year-old former head girl Georgia Williams in 2013.

The story of two friends, Sarah Williams and Katrina Walsh, who carried out the evil and jealousy-fuelled murder of businesswoman Sadie Hartley at her home in Helmshore, Lancashire.

In a tiny hamlet in Cornwall in October 2000, police found the bodies of Lesley Ford and her four children, a chilling discovery that would leave officers and the whole nation shocked.

The story of 27-year-old Pawel Relowicz, who sexually assaulted and killed 21-year-old Hull student Libby Squire while she was on her way home in a case that made headlines around the UK.

Comparing himself to Freddy Krueger, Daniel Gonzalez wanted to become a notorious serial killer and took the lives of four people during a chilling two-day spree of violence in 2004.

The story of serial killer Geoffrey Evans and his accomplice John Shaw, who moved to Ireland to avoid a UK police investigation and murdered two women in 1976 while planning to kill more.

The chilling story of Mark Martin, who became known as the 'Sneinton Strangler' when he murdered three homeless women in his quest to achieve notoriety as Nottingham's first serial killer.

The story of Malcolm Green, who was jailed for life for the brutal murder of a Cardiff sex worker, only to kill again when he was released from prison after 18 years behind bars.