A look at the key errors made by murderers that led to their arrest, focusing this time on Paul Hutchinson, who abducted, raped and strangled Colette Aram in 1983.
A look at how police tracked down Stephen Port, the east London serial killer responsible for murdering at least four men and committing multiple rapes.
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.
