Examination of the police investigation into the murder of Rachel Nickell, who was stabbed to death on Wimbledon Common in 1992. A crime for which, at the time of this programme, no one had ever been convicted. Former Detective Inspector Keith Pedder, who has since left the force, discusses his controversial and widely criticised handling of the case, and one-time suspect Colin Stagg reveals how it affected his life. (thetvdb.com)