Please note this is a region 2 DVD and will require a region 2 (Europe) or region Free DVD Player in order to play.r r From the Director of Broadchurch and the producer of Line of Duty comes Code of a Killer .r r The gritty telling of the extraordinary true story of Alec Jeffreys discovery of DNA fingerprinting and its first use by Detective Chief Superintendent David Baker in catching a double murderer.r r David Threlfall (Shameless) takes the role of David Baker who between 1983 and 1987 headed up the investigation into the brutal murders of two Leicestershire schoolgirls, Lynda Mann and Dawn Ashworth.r r Only a few miles away, Dr Alec Jeffreys, played by John Simm (Prey), was a scientist at Leicester University who, on 10 September 1984, invented a remarkable technique to read each individual's unique DNA fingerprint.