Code of a Killer, ITV, David Threlfall


Test-tube detectives – John Simm and David Threlfall


A drama based on real events that is truly an awe-inspiring story…

★★★★ ITV, starts Monday, 6 April 9pm

ITV HAS  a fine track record at taking true crime cases and – sometimes controversially – turning them into thought-provoking, compelling dramas.

Past successes include This Is Personal: The Hunt for the Yorkshire Ripper, Appropriate Adult and, most recently, The Lost Honour of Christopher Jefferies.

This latest, Code of a Killer, is the story of Alec Jeffreys’ discovery of DNA fingerprinting in the 1980s alongside its first use by Detective Chief Superintendent David Baker in nabbing a double murderer. You could say it cleverly splices the DNA of two dramatic genres – the great inventor biopic and the police procedural.

Either story has the potential to be great viewing. Here we get both.

David Threlfall and John Simm

It begins in 1983 with the murder in a small village outside Leicester of 15-year-old Linda Mann, who was raped and strangled. David Threlfall – a long way from Frank Gallagher in Shameless here – manages to be charismatic as the ordinary, hangdog detective leading the exhaustive and fruitless hunt for the killer.

Baker and his team at the second crime scene

Baker and his team at the second crime scene

Meanwhile, John Simm leaves behind his familiar dour, hard-bitten routine to play the absent-minded scientist Jeffreys. His wife is infuriated by his neglect of parental duties, but Simm’s performance brilliantly captures the lone, eccentric scientist obsessed with uncovering a decipherable method for the DNA code.

Jeffreys was the sort of boy who brought home dead cats found on his paper round to dissect on the kitchen table. As the eccentric beardy grown-up scientist, John Simm is pretty likeable, for once.

DNA fingerprinting

The pace of the opening 90-minutes is hectic, as it moves between Jeffreys’ frustrations in cracking the code and the heartrending police investigation.

John Simm as Jeffreys

John Simm as Jeffreys

Three years later another local murder, that of 15-year-old Dawn Ashworth, gives the inquiry fresh impetus. The investigation takes a perplexing turn, however, when a suspicious young man confesses to the murder of Dawn, but not to that of Linda.

Baker has been reading about Jeffreys’ work, just a few miles away, in a local newspaper, and the detective contacts him. Could his new-fangled DNA coding test, initially only used to test parentage in an immigration case, confirm whether the police have got their man?

It’s ironic how many landmark inventions were not intended for the purposes their inventors imagined. From Viagra (designed as a treatment for high blood pressure) to the internet (a communication tool for nerds), it’s astonishing how often breakthroughs have hit unseen but much greater targets.

Stumbling on a new use for genetic coding

The same is true of Jeffreys’ pioneering work. Until Baker gets in touch, DNA coding was being used to settle immigration and paternity disputes.

It’s a great moment in Code of a Killer when the two finally meet. Jeffreys initially doubts the use of his test to help the police. He has no idea whether the DNA in a semen sample will have deteriorated in the three years since the first murder.

We now know what a revolutionary effect DNA fingerprinting has had on criminal detection. This absorbing two-parter is a startling reminder of the tragic events and brilliant labours that led to it.

See the Code of a Killer trailer in the post below

Interview with David Threlfall about Code of a Killer in The Independent


  1. Geoff says:

    This is my go to blog for UK series thanks for doing this each year. And now it doesn’t take a kazillion years to load the page which makes it all the better. Cheers

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