The murder of four members of the Ding family by Anxiang Du in Northamptonshire in 2011, focusing on the key error that he made which led to his arrest.

A look at how the Thames Valley Police investigated the death of a wealthy Oxford antiques dealer and ultimately tracked down and caught his killer.

The story of how, in 2009, police closed the net on Anthony Sowell, the prolific American serial killer known as the Cleveland Strangler.

An in-depth look at how police brought Tony McCluskie to justice after he murdered and dismembered his sister, EastEnders actress Gemma McCluskie, in 2012.

An in-depth look at how Arizona serial killer William Inmon was brought to justice after killing three people.

The story of how police closed the net on rogue cop Kent McGowen after he killed a woman at her home in Houston in 1992.

A look at how police tracked down Stephen Port, the east Londoner responsible for murdering at least four men and for committing multiple rapes.

A closer look at the subtle clues that led police to Jesse Matthew, a former cab driver who kidnapped and killed two Virginia college students.

In an idyllic place - a mother disappears from the family home…the front door was left open. She was meant to be collecting her child from school but she didn't turn up. The police were called to the home later that evening, Nat Fraser her husband had been staying elsewhere at the time of her disappearance. A missing person investigation began, but the evidence didn't stack up and detectives began to fear she had been abducted and murdered.

A look at the key errors made by murderers that led to their arrest starts with Paul Hutchinson, who abducted, raped and strangled Colette Aram in 1983.