Episode 2

S1, E2: Conclusion of a two-part drama telling the true story of how a brilliant scientist and pioneering detective united to create the most significant advance in modern criminal investigation. DCS David Baker is leading the search for the murderer of two schoolgirls. When a teenager admits to one of the murders but not the other, Baker asks Dr Alec Jeffreys to analyse the DNA evidence left at the crime scenes. Both men are shocked to discover that the teenager is innocent and his confession false. The main suspect is released to a storm of controversy. Convinced the killer is local, and armed with his DNA fingerprint, Baker proposes testing the blood of over five thousand local men in order to seek a match. But Baker and Jeffreys face huge opposition from sceptics in the police and community and opponents in the establishment to such an expensive and controversial plan. Can the two men convince their opponents - and persuade over five thousand men to voluntarily take the blood test?