Fifty years after the brutal deaths of siblings Griff and Martha Thomas at their remote Pembrokeshire farmhouse, new questions are being raised about whether they were the first victims of notorious serial killer John Cooper, known as the “Bullseye Killer.” While the original investigation concluded Griff Thomas killed his sister before taking his own life, the family and locals have long disputed this, believing both were murdered. Now, a second cousin is pressing authorities to formally consider John Cooper’s potential involvement.
The Discovery and Original Investigation
In December 1976, 19-year-old postman Nigel Rossiter discovered the grim scene at the Thomas siblings’ farm in Llangolman. He found the charred remains of 73-year-old Griff Thomas in the kitchen. Police later discovered the body of his younger sister, 70-year-old Martha, also deceased at the property. Initially treated as a double murder, the investigation took a different turn weeks later. Authorities concluded that Griff had bludgeoned Martha with a chair before setting a fire and dying in it himself. This conclusion was met with strong resistance from the siblings’ grieving family and their community, who insisted the devout and peace-loving siblings would never have harmed each other.
Family’s Persistent Doubts and New Claims
Huw Gibby, the second cousin of Griff and Martha, has exclusively shared his family’s enduring belief that John Cooper was responsible for their deaths. Cooper, who was later convicted in 2011 for four murders, two sex attacks, and numerous burglaries, was reportedly working on local farms, including the Thomas siblings’ property, repairing fences around the time of their deaths. Gibby asserts that Cooper would have been aware of the siblings’ habit of leaving their doors unlocked and keeping cash on the premises to pay farmhands.
Gibby has presented what he calls “12 reasons” to Dyfed-Powys Police, arguing for a reinvestigation into the deaths with Cooper as a suspect. He specifically challenges the original theory that Griff, who suffered from frailty and a condition that impaired his grip, could have wielded a heavy oak chair to kill his sister. “There is no way on earth that Griff would have killed Patti (the family’s name for Martha),” Gibby stated, emphasizing Griff’s deep affection for his sister. He also questioned the manner of Griff’s supposed suicide, describing the alleged self-immolation as “plain ridiculous” and pointing to evidence of blood near Griff’s head, which he believes contradicts the suicide narrative.
The family’s theory suggests that an unknown third party, likely Cooper, murdered Martha while Griff was away purchasing groceries. Upon his return, Griff would have also been killed. Gibby’s frustration with the current review process is palpable. He claims a detective dismissed his suspicions, stating, “Don’t you dare mention his name,” and that any suggestion of Cooper’s involvement could jeopardize the ongoing investigation. Consequently, Gibby has enlisted his own forensic and fire specialists and is pursuing a fresh inquest through the Attorney General.
The Bullseye Killer’s Known Crimes
John Cooper, a diagnosed psychopath, gained notoriety for a series of brutal crimes committed in Pembrokeshire during the 1980s. His conviction in 2011 followed a cold-case review, Operation Ottawa, initiated by Dyfed-Powys Police in 2006. Cooper received a whole-life sentence for the murders of:
- Richard and Helen Thomas: Shot dead in their Scoveston Park farmhouse in December 1985, with their home subsequently set on fire. This incident occurred just a few miles from where Cooper lived.
- Peter and Gwenda Dixon: Shot at close range in June 1989 while walking the coastal path near Little Haven, Pembrokeshire, where they had been camping.
Cooper’s moniker, “The Bullseye Killer,” stemmed from his appearance on the darts-themed television game show “Bullseye” just a month before the Dixon murders. He was also convicted of a sex attack on a 16-year-old girl and indecent assault on a 15-year-old girl in Milford Haven in March 1996. Crucially, forensic evidence, including traces of Peter Dixon’s blood found on a shotgun owned by Cooper and on his clothing, along with significant textile-fibre links, connected him to the Pembrokeshire murders and the assaults.
Police Response and Ongoing Review
Dyfed-Powys Police have confirmed that a “significant amount of complex work” has been undertaken as part of a forensic review process. They have stated that the family of Griff and Martha Thomas has been kept informed of the progress. The force has conducted detailed searches of various archives, including police stations, the National Archive of Wales, and the Forensic Science Service Archive, to retrieve original documents and evidence. These searches yielded items such as Martha’s diaries, original investigation files, and postmortem moulds.
The police acknowledge the challenges in reviewing an incident from 50 years ago and are currently in communication with HM Coroner to discuss how to proceed. They have committed to continuing to update the family on the review’s findings and any recommendations from the coroner.
Conclusion: A Lingering Mystery
The deaths of Griff and Martha Thomas remain a deeply painful and unresolved chapter for their family and the Pembrokeshire community. While authorities have conducted extensive reviews and forensic examinations, the family’s persistent advocacy for a formal investigation into John Cooper’s potential involvement highlights the enduring questions surrounding the case. The outcome of the ongoing dialogue with HM Coroner will be crucial in determining whether a fresh inquest or further investigation will bring the clarity and justice the family has sought for half a century.
