Pembrokeshire Murders, Episode 3 review: painstaking realism, but the paperwork just isn’t that dramatic

We walked into the final part of The Pembrokeshire Murders (ITV) knowing who did it, knowing he was in custody and feeling pretty sure of the outcome of the trial. So what was left?

This last stretch attempted to increase the tension with an interrogation scene and a race against time to find a crucial piece of forensic evidence. But there was nothing here to keep us riveted, not even Keith Allen’s skillful trick as the bad little killer.

What this three-part drama managed to convey is the sheer amount of police work that went into this cold affair and DCI Steve Wilkins (Luke Evans) determination to put John Cooper behind bars.

The script, however, was professional at best. Because the focus was on Wilkins throughout and the crime was revisited after many years, there was no attempt to tell us anything about Cooper’s victims. All we’ve seen of Peter and Gwenda Dixon, shot dead on a coastal walk, are photos of their blood-soaked clothes. About Richard and Helen Thomas, the siblings killed in their home, we have learned even less.

Cooper had also held a group of teenagers at gunpoint, raping one and sexually assaulting another. These two women bravely stepped forward to testify at the trial, meaning the characters appeared on screen. But their mention of another member of the group who died on the eve of the trial – “his health finally failed” – was sketchy. We haven’t been told anything more about her, just as a mention in Episode 1 of Wilkins’ terrible time with the Metropolitan Police was never mentioned again.