New Sky Documentary The Pembrokeshire Murders (w/t) sheds fresh light on a landmark case involving two double murders

A high-profile police investigation led to John Cooper’s conviction. Now, two Pembrokeshire locals are uncovering evidence they believe could point elsewhere

Wednesday 26 August 2026

New Sky Documentary The Pembrokeshire Murders (w/t) sheds fresh light on a landmark case involving two double murders

Sky today announces the commission of documentary series, The Pembrokeshire Murders (w/t), coming to Sky Documentaries and streaming service NOW later this year.  

Produced by Magna Studios, this three-part documentary series re-examines evidence from this landmark investigation and asks important questions about a case that was closed in 2011.  

In the 1980s, the coastal community of Pembrokeshire was shaken by two double murders. Siblings Richard and Helen Thomas were killed at their home in 1985; four years later, Peter and Gwenda Dixon were murdered whilst walking on the Pembrokeshire Coast Path. 

For years, the murders remained unsolved until, in 2011, local man John Cooper was convicted following a headline-making police investigation, renowned for its pioneering cold-case detective work. A decade later, the case was once again in the national spotlight with ITV drama The Pembrokeshire Murders. 

Among those watching the drama in 2021 were two Pembrokeshire locals – journalist Andy Chandler and legal assistant Hayley Wood. Independently, both began wondering whether Cooper could have been responsible for more crimes. But after joining forces, their investigation took them in an unexpected direction, uncovering material from Cooper’s original defence case that they believe raises new questions about his convictions and points to other possible suspects. The police, however, remain confident they have the right man and question whether material examined decades later, without the full context of the original investigation, can challenge the conclusions reached at the time. 

Do Andy and Hayley's findings raise legitimate new concerns about Cooper’s convictions, or are there other explanations for what they have uncovered? The Criminal Cases Review Commission (CCRC) is now reviewing material relating to the case. 

With access to Hayley and Andy as they pursue their investigation, alongside those involved in the original police investigation, The Pembrokeshire Murders (w/t) brings together previously unseen material and archive, first-hand testimony and expert insight to examine the competing perspectives surrounding the case. At its heart is a question about the line between belief and certainty – and what happens when new questions are raised about something that had appeared settled. 

Hayley Reynolds, Head of Documentary Commissioning at Sky, said: “Hayley and Andy are two Pembrokeshire locals whose search for answers about crimes that have loomed large in their community for decades takes them somewhere entirely unexpected. What they uncover raises important new questions, turning their investigation into a compelling search for the truth."

Louis Mole, Creative Director, Magna Studios, said: "Stories of this scale demand a cinematic sensibility, but also the rigour of journalism and a genuine exploration of the truth. This series embodies Magna’s approach: telling gripping, human stories through the different perspectives of those who lived them, with the craft and integrity to engage and challenge audiences."

The Pembrokeshire Murders (3x60) was commissioned by Phil Edgar-Jones, Executive Director, Unscripted Originals at Sky for Cécile Frot-Coutaz, Chief Advertising and Content Officer, CEO Sky Studios. The Head of Documentary Commissioning is Hayley Reynolds and the Commissioning Editor for Sky is Bruce Fletcher. The Pembrokeshire Murders (w/t) is produced by Magna Studios. Tash Gaunt serves as Series Director with Louis Mole, Sarah Macdonald and Jonathan Smith serving as Executive Producers. Stuart Bernard serves as Showrunner, Sam Taylor as Producer, and Kiyomi Taylor as Production Executive. 

The Pembrokeshire Murders (w/t) comes to Sky and streaming service NOW later this year

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