CATCHING BRITAIN’S KILLERS: THE CRIMES THAT CHANGED US

BBC Two, 9.00pm

The craze for true-crime documentaries shows no sign of abating, but this new three-part series gets off to a fascinating start with the story of how DNA fingerprinting was established as a crucial new forensic technique. In November 1983, 15-year-old Lynda Mann was raped and strangled in a small Leicestershire village, but in the absence of witnesses and physical evidence, there were neither leads nor suspects. Then, three years later, Dawn Ashworth, also 15, suffered the same appalling fate. With a local teenager in custody but his confession contended, the force’s lead detective David Baker got desperate enough to take a punt on a relatively untested technique developed by a local academic,

Alec Jeffreys.

The story was dramatized in ITV’s Code of a Killer in 2015, with John Simm as Jeffreys and David Threlfall as Baker, but there’s a charge to seeing both the men themselves and Dawn and Lynda’s relatives onscreen, plus a valuable look forward to further advances involving everyone from the Romanovs to Michael Howard, that makes this particularly compelling. Gabriel Tate

Inventor: professor Alec Jeffreys transformed forensic science