Based on 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. David Threlfall, John Simm, Anna Madeley, Andrew Tiernan, Lorcan Cranitch, Dorothy Atkinson, Neil Edmond Added on BritBox 2022-04-08. Added on Amazon Prime 2020-09-17. Youtube Trailer