The Pembrokeshire Murders - a new ITV drama series adapted from a true crime book 'Catching the Bullseye Killer' tells the story of the extraordinary lengths a police force went to to catch a serial killer.
The three-part series sees Hollywood actor Luke Evans play Detective Superintendent Steve Wilkins, who in 2006 led a cold case investigation into two double murder cases from twenty years before.
Employing pioneering forensic methods, Wilkins and his team found microscopic DNA and fibres that potentially linked the murders to a string of burglaries committed in the 80s and 90s.
The perpetrator of those robberies was nearing the end of his prison sentence, but if Steve Wilkins was right, he was also a serial killer.
Luke Evans said it was a "privilege" to be playing the role in the drama.
“It is a privilege to be playing the role of Steve Wilkins in The Pembrokeshire Murders and working again with Simon Heath, his team at World Productions and ITV. It’s a huge responsibility for me as the drama depicts a true crime which to this day still affects the families of those whose lives were tragically taken.”
ITV Wales journalist and presenter Jonathan Hill, who covered the case as a journalist at the time spend the last year working with the production company to turn his book into the ITV drama.
The first episode, which aired on Monday, launched with 6.3m viewers - the channel’s biggest overall Drama overnight audience since Vera in 2018 and biggest new Drama first episode overnight audience since The Durrells in 2016.
Jonathan had special access to the set and the stars as they filmed in Wales.
Owen Teale, who plays barrister Gerard Elias said, "When you're there doing it, you must never forget that this really happens to people. It's not a made up story, it's not a fantasy. "
"This is reality and have a heart for them, for people that this has affected", Teale added.
Caroline Berry, who plays Cooper's wife said, "But I do remember that because I know especially the murders on the coastal path were particularly shocking because these were two people just on the last day of their holiday enjoying their last walk and to be executed like that I mean, shocking, in a place of beauty, that people go to relax and enjoy, awful.
Keith Allen, who plays John Cooper said, "I'm not trying to do an impression of the guy you know. But on the back of your mind, there is and I guess there should be an awareness that there are people who were his victims who are still alive who will watch this so you can't be flippant about it at all. You can't showboat."
Luke Evans added, "It is a powerful story and it's a success story when it shows you how people come together and when the truth is there as deeply as it was buried, if people have a passion and a want to find the truth, they'll find it. I hope we've done it justice, I really do."
The drama continues Tuesday and Wednesday night at 9pm on ITV which is followed by a documentary on Thursday 14 January.