Luke Evans is dogged but bland as detective Steve Wilkins who reopened two unsolved murders dating back to the 1980s. The main suspect is John Cooper already in prison for other crimes and due to be paroled soon. A fast moving drama about the real life conviction of Cooper. Keith Allen is rather creepy as Cooper. There is reliance on advances in DNA and good old fashioned police work. The drama condenses the five years investigation carried out by Wilkins. It is reluctant to criticise the original police investigation which looked flawed.