On the morning of Thursday, June 29, 1989, Peter and Gwenda Dixon left their tent at Howelston Caravan Park, near Little Haven in Pembrokeshire, at about half past nine. It was the last day of their holiday. The tent was wet, so they decided to leave it to dry and take one more walk along the coast path before driving home to Witney in Oxfordshire. They did not come back. Six days later two police dog handlers found their bodies in thick cover on a cliff-top plateau a short distance from the path.
Three and a half years earlier, four days before Christmas 1985, a farmer named Richard Thomas and his sister Helen had been shot in their three-story farmhouse at Scoveston Park, outside Milford Haven, a few miles across the county. The house was set on fire with them inside it. Neither case was solved for more than twenty years. When the two double murders finally came to trial at Swansea Crown Court in 2011, the man in the dock was a 66-year-old laborer from Letterston named John William Cooper, who had been living within a few miles of all of it. The evidence that convicted him had, for the most part, been sitting in police storage since 1998.
Cooper was born in Milford Haven on September 3, 1944, according to the Pembrokeshire Herald. The jury at his trial heard that he left school at fifteen and worked in a range of trades. He married Patricia, known as Pat, in 1966, and they had two children, a son, Andrew, and a daughter.
In 1978, while he was working as a welder's mate at the Gulf oil refinery at Milford Haven, Cooper won £90,000 and a new car on a spot-the-ball competition, the BBC reported from the trial. (Crime+Investigation gives the figure as £70,000.) He soon left his job to set up a family smallholding. The prosecution's case was that he lost the money through a series of house moves that cost him money and through gambling. Asked in the witness box whether he had gambled away a lot of money, he said: "No, it would not be right to say that." By 1983, police said, he had started committing burglaries.
Cooper liked fishing and the outdoors. For much of the 1980s and 1990s the family lived at 34 St Mary's Park, Jordanston, near Milford Haven; Andrew Cooper told the jury they had also lived at Rosemarket and Hazel Beach. He told the court that his father watched survival programs on television, kept an SAS survival handbook and quoted from it, and kept a locked rear room that the children were told not to enter. When Andrew once went in, he said, he found gun barrels in a vise, burned coins and jewelry, and items that "appeared to belong to other people." He described his father as "a very, very strong man, a very fit man, a loud and aggressive man." He left home at sixteen or seventeen to live with his grandmother. In later interviews quoted by Crime+Investigation, he described being beaten as a child; that account was not tested in court and is his alone.
Richard Thomas was 58 and farmed at Scoveston Park, near Milford Haven. His sister Helen, 54 by most accounts, lived with him in the large three-story house there. The Daily Post, writing at the end of the trial, described them as a chapel-going brother and sister, an old-fashioned couple who kept cash at the farm to pay casual laborers and suppliers. Richard Thomas also owned a second property, Norton Farmhouse.
Cooper was not a stranger to them. The Court of Appeal recorded that he had worked for Richard Thomas in the early 1980s. A farm laborer, Neil Evans, told the jury that Cooper sometimes came to Scoveston Park to buy hay, and that he had once seen Cooper and Richard Thomas argue over its price.
On the evening of Sunday, December 22, 1985, emergency services were called to a large fire at Scoveston Park. When it was brought under control early the next morning, the bodies of the brother and sister were recovered. Post-mortem examinations found that both had been shot with a 12-bore shotgun. The prosecution's account, given at trial by Gerard Elias QC, was that a burglar had targeted the house, probably knowing Helen Thomas was alone; that Richard Thomas came home and disturbed him; that he was shot, probably in an outbuilding, and his body dragged into the house; and that diesel was poured around the building and set alight. The house was so badly damaged that it was later demolished. A new house now stands on the land.
Dyfed-Powys Police launched a murder inquiry. At its peak in 1986 it had 150 officers. Nobody was charged. For years many people in the county assumed the deaths were a robbery that had gone wrong, and the case went cold.
Peter Dixon was 51 and Gwenda Dixon was 52. They lived in Witney, Oxfordshire, and had two grown children, Tim and Julie. Pembrokeshire was where they went on holiday; the Daily Post called it "what they regarded as their West Wales paradise." In June 1989 they were at the end of a two-week camping holiday at Howelston.
After they were last seen leaving their tent on June 29, the campsite owner became worried when they did not come back for it. On July 2 their son Tim rang the site to check on them and then reported them missing. On July 5, at about 3:30 in the afternoon, two dog handlers, Michael Calas and Gwyndaf Lewis Jones, were searching a section of the path just west of Little Haven when they left the path and went down to a plateau on the cliff edge. They found Gwenda Dixon first and then her husband.
The pathologist, Professor Bernard Knight, told the jury that both had been shot at short range with a 12-bore shotgun, Peter Dixon three times and Gwenda Dixon twice. Peter Dixon's hands had been tied behind his back. The bodies had been hidden under a screen of cut branches and foliage. The prosecution alleged that Gwenda Dixon had also been sexually assaulted, either before or after she died.
Peter Dixon's NatWest cash card had been taken, and his PIN had been forced from him. The card was used or tried four times over three days: twice in Pembroke on the day of the killings, then in Carmarthen and Haverfordwest. His wedding ring was taken too.
The murders drew national attention. On July 10, at a second press conference, Tim Dixon appealed for information, and police released an artist's impression of a man seen in the area, a cyclist who had used Mr Dixon's card. By July 18 police had received more than 1,700 calls. The BBC's Crimewatch appeal drew a large response, and Dyfed-Powys Police hired a plane to patrol the area, the Daily Post said, partly to reassure visitors. Theories filled the gap. One held that the Dixons had stumbled on a hidden cache of IRA weapons. Another, recalled by Crime+Investigation, was that they had interrupted a drug gang. A profiler, Professor Canter, was brought in. On the first anniversary in June 1990, police handed questionnaires to residents and holidaymakers over two weeks. The cyclist was never traced.
Some weeks before the Dixons were killed, Cooper had been a contestant on Bullseye, the ITV darts quiz show presented by Jim Bowen. The timing is given differently in different reports: the BBC's 2011 profile says the episode was recorded two months before the murders, while the BBC in 2023 and ITV News said he appeared a month before, and Crime+Investigation says less than four weeks. On the show Cooper told the host that his unusual hobby was scuba diving.
The footage became important only two decades later. Detectives in the cold-case review found it and compared his appearance on screen in 1989 with the artist's impression of the man who had used Peter Dixon's card. At trial the prosecution played the clip to the jury. Its argument was that Cooper's appearance at the time matched the man seen at the cash machine.
The Bullseye clip was never identification evidence in the strict sense, and the trial judge said so. According to the Court of Appeal, Mr Justice Griffith Williams told the jury not to use the image to identify the defendant. The most that could be proved, he said, was that one witness's description was similar in some respects to how Cooper then looked, and it was "a huge evidential leap from that evidence to the conclusion that the man was the defendant." The last defense witness at the trial, a retired police officer named Emlyn Dudley, told the jury that Cooper did not resemble the artist's impression. The clip is the detail most people remember about the case, but the conviction rested on forensic links, not on the footage.
On the evening of March 6, 1996, five teenagers, three girls and two boys aged fifteen and sixteen, were walking through a field near the Mount Estate School in Milford Haven when a man in a balaclava and gloves, carrying a torch, approached them and pulled out a sawn-off double-barreled shotgun. He ordered them to lie face down and demanded money. He raped a sixteen-year-old girl at knifepoint and indecently assaulted a fifteen-year-old girl. As he left he fired the gun into the air and threatened to kill them if they told anyone, saying he knew who they were. An incident room was set up at Haverfordwest under Detective Superintendent Aldwyn Jones. The case remained unsolved. The teenagers were not named in court reports, and they are not named here.
By the mid-1990s a long run of burglaries in the same small area of Pembrokeshire had police looking for one offender. On an evening in November 1996 a man in a balaclava, carrying a shotgun, entered the home of Sheila Clark (spelled Clarke in some reports), a woman in her early sixties, at Sardis near Milford Haven, while she was waiting for her husband to come home. He assaulted her, tied her up and ransacked the house, taking jewelry and a handgun. He left by a prepared route through fences that had been cut in advance. A witness, John Monroe, chased him until the man threatened him with the gun. Next day a police dog followed the track toward Cooper's home.
Along that route, which the prosecution later called a "robber's run," and in hedgerows near the house, police recovered a sawn-off shotgun, a balaclava, a fleece jacket, gloves and other items. Cooper used hedges and field edges as hiding places for stolen goods and as escape routes, the prosecution said; the BBC summed the theory up as hedgerows used as "safes." On January 21, 1998, he was charged with a series of burglaries and the armed robbery, an inquiry Dyfed-Powys Police called Operation Huntsman. Officers searched his house and grounds that month and took away many items, including a pair of shorts from his bedroom. Buried in a tin in the grounds they found wartime shotgun cartridges and bullets similar to ones Richard Thomas had kept.
On December 10, 1998, at Swansea Crown Court, Cooper was sentenced to sixteen years for thirty burglaries and the Sardis robbery. In January 2000 the Court of Appeal dismissed his appeal against three of those convictions. In a 2005 prison assessment, a forensic psychiatrist, Jennifer Bunton, recorded him as admitting break-ins at garages and commercial premises, though not at homes, and saying he had started after his wife was injured in an accident in 1986 and could no longer work. Under cross-examination at the murder trial, she agreed with the defense that many prisoners believe they must make some admissions to win parole.
In February 2006 Dyfed-Powys Police formed a small team to review the force's unsolved serious crimes in Pembrokeshire. It was named Operation Ottawa. Its brief covered three cases that had never been formally linked: the Thomas murders, the Dixon murders and the Mount Estate attack. It was led by Steve Wilkins, then a detective superintendent and by the time of the trial a detective chief superintendent.
The team spent about two years recovering, cataloguing and recording every piece of material from the old investigations. On November 8, 2007, it held a press conference at Haverfordwest to describe its work and renew appeals for witnesses. The detectives came to believe the three crimes were the work of one man: someone who knew the countryside closely, carried a shotgun and rope, and was prepared to control several victims at once. The Huntsman burglaries covered the same ground, and Cooper's former home at St Mary's Park sat, in the prosecutor's words, "in the very epicentre" of the offenses.
Because of Huntsman, a large body of potential evidence was already in police hands. The shotgun from the hedge near Sardis, the gloves, the clothing and the shorts from Cooper's bedroom were sent for fresh examination using techniques that had not existed in 1985, 1989 or even 1998. In June 2008 Cooper was brought out of prison and interviewed over four days at Ammanford about the murders and the Mount Estate attack. Transcripts read to the jury later showed that he denied all of it. He said he had never been anywhere near Scoveston Park, then accepted he might have been there a few times. He denied that a wedding ring he had sold to a jeweler in Pembroke had belonged to Peter Dixon.
Cooper had served about ten years. He was released on license a few months before May 2009 (Crime+Investigation says January 2009). While he was free, the laboratory work came in. On April 23, 2009, detectives received the first call from LGC Forensics about significant findings. The forensic scientist Angela Gallop, whose work features in later documentaries, was among those involved. More results followed through April and May.
The findings that the jury later heard were these. Specks of blood found on the sawn-off shotgun recovered near Sardis, under black paint that had been applied to it, matched Peter Dixon's DNA profile; the prosecutor told the jury the chance of it being someone else's blood was one in a billion. The shorts seized from Cooper's bedroom in 1998 carried a bloodstain matching Peter Dixon. When scientists unpicked the hem, they found a trace of body fluid matching the profile of Julie Dixon, the couple's daughter. The prosecution's case was that the shorts belonged to the Dixon family, that Cooper took them from the cliff-top in 1989, and that he had worn them as his own ever since. Cooper told police the shorts were his. Crime+Investigation reports that the hem had been shortened, which is why the original fabric had been preserved inside the fold.
There was also fiber evidence. Fibers from a glove found in a hedge near Cooper's home matched fibers on the branches used to hide the Dixons' bodies and on their clothing. Fibers matching a sock worn by Richard Thomas were found in a pocket of the shorts. A sock belonging to Richard Thomas had been found hidden in a hedgerow near Cooper's house. Fibers from gloves linked to Cooper were found on the clothing of the two girls attacked at the Mount Estate, and fibers transferred the other way, from their clothing to the gloves. A key found at Cooper's home fitted a lock at Norton Farmhouse, Richard Thomas's other property. A shotgun cartridge box found in his home bore handwriting the prosecution said could match Helen Thomas's. The prosecution's fiber expert, Roger Robson, told the jury he "had never worked on a case with as many links as this."
On May 13, 2009, Cooper was arrested and charged with the four murders, the rape and indecent assault at the Mount Estate, and five attempted robberies arising from the same attack. As he was led into Haverfordwest Magistrates' Court two days later, he shouted at waiting photographers and camera crews: "You must judge me after the trial and not before." He was remanded in custody and appeared at Swansea Crown Court on May 27, 2009.
The trial was first fixed for March 2010, then put back to October 2010 and again to March 2011. Before it began there was a legal question about the Huntsman convictions, since much of the Crown's case depended on items recovered after the Sardis robbery. On December 17, 2010, the Court of Appeal ruled that Cooper was entitled to try to show the new jury that he had not committed the Huntsman offenses, despite having been convicted of them. Because of those convictions, it would be for him to prove that it was more likely than not that he was innocent of them.
The trial opened at Swansea Crown Court on March 21, 2011, before Mr Justice Griffith Williams. Gerard Elias QC prosecuted and Mark Evans QC defended. Elias called the killings "merciless executions for pitifully small gain" and told the jury that each crime "involved the use of cold, calculating violence." He said the offender was plainly a local man who "knew the area like the back of his hand," knew of the hideaway near the coast path, knew he had time to drag Richard Thomas's body inside and pour diesel through the house, and came prepared with rope and a shotgun. Each incident, he said, involved a shotgun, ropes and a balaclava, and at none of the scenes had a spent cartridge been left behind. He suggested the teenagers at the Mount Estate may have been spared only because there were too many of them.
The jury visited the coast path near Little Haven on April 5 and the Scoveston Park site the next day, and was shown Cooper's house. The jurors had computer screens laying out the forensic links between exhibits. Andrew Cooper gave evidence by video link. He described his father going out at night in dark clothes with a shotgun slung under his shoulder, and said a shotgun shown to him in court was similar to it. Under cross-examination he accepted that in earlier statements he had said he did not recognize the gun. Mark Evans put it to him that he was "making this up as you go along." "Not at all," he replied. "I've got nothing to gain from this, nothing at all. I don't really want to be here."
The defense attacked the forensic case on contamination. Cross-examining Robson, Evans suggested fibers could have been transferred between exhibits that had been opened and repackaged over the years. Robson agreed that accurate records should always be kept of when exhibits were opened, examined and repacked, but said it was "not untypical for old cases for this not to happen on every occasion."
Cooper gave evidence. He said the Sardis shotgun was not his, that he had not modified it, and that he had been wrongly convicted of the robbery. He told the jury he had limited movement in his left arm from arthritis at the time and was often in severe pain. Asked how he had injured his hands and face around the time of the Sardis robbery, he said he had fallen into a dead Christmas tree in his grounds while tending his chickens. "Do you make things up as you go along?" Elias asked. Cooper said his son was mistaken about the shotgun walks. A large part of his defense rested on witness descriptions of the Sardis robber, of the man using the cash card in 1989 and of the man at the Mount Estate, which his counsel argued did not fit him.
The judge began his summing-up on May 23, 2011. On May 26, after an eight-week trial, the jury convicted Cooper on all counts: four murders, rape, indecent assault and four counts of attempted robbery.
Passing sentence the same day, Mr Justice Griffith Williams described what the victims must have gone through. Cooper interrupted him. "This is utter rubbish, it's rubbish," he shouted. "That jury's been on the internet. I don't blame them, evidence has been kept from that jury." The judge warned that he would be taken down to the cells if he did not keep quiet, and Cooper stayed in the dock to hear the rest.
"The murders were of such evil wickedness that the mandatory sentence of life will mean just that," the judge told him. He imposed life imprisonment with a whole life order, meaning Cooper will never be eligible for release. "You are a very dangerous man, a significant risk of serious harm," he said, and described him as "highly predatory" and a man who, "but for advances in forensic science, may well have continued to evade capture." For the Mount Estate offenses he received concurrent terms of fifteen years for rape, eight for indecent assault and seven for attempted robbery.
When Elias read the victim impact statements, members of Cooper's family walked out of court, several in tears. As they left, his brother called out: "We're here for you, John."
Tim Dixon and Julie Ann Pratley described their parents as "loving, gentle and charismatic." "They had wisdom, humour and were compassionate," they said. "Even after two decades their absence is immense and still painful." They said the people of Pembrokeshire owed the police "a debt of gratitude."
The Thomas family said its loss had deepened over the years. "As a family, we would wish that justice is done for Richard and Helen," they said in a statement issued through the police. "Memories will remain with us all forever but we hope that we will now be able to remember the happier times more than the very sad ones."
Gareth Rees, one of the detectives who interviewed Cooper in 2009, told an S4C program in 2016 that he was still in touch with the Dixon family and met them each year when they came back to Pembrokeshire to remember their parents.
Cooper's lawyers sought leave to appeal against the convictions. A single judge refused, and the application was renewed before the Lord Chief Justice, Lord Judge, sitting with Mr Justice Wilkie and Mr Justice Singh, on October 17, 2012. Mark Evans QC argued that the jury had been "profoundly misdirected" and that there was "clear room for confusion" in its mind. The single ground concerned one passage in the summing-up about witness descriptions. The judge had told the jury that if a description was or might be inconsistent with Cooper's appearance at the time, they should "put it out of mind." The defense said this undercut its main argument, that the descriptions showed Cooper could not have been the offender. Counsel also questioned the comparison between the Bullseye footage and the artist's impression.
In a judgment handed down on November 1, 2012, the court accepted that, taken out of context, the passage was "a slip of the tongue." Read as a whole, it held, the summing-up had put the defense argument to the jury clearly and fairly, and there could never have been "the slightest doubt" about how the jury was invited to use the description evidence. It described Peter Dixon's blood on the shotgun and the shorts as "virtually incontrovertible evidence" linking Cooper to the Dixon murders, and said the jury had heard "an exceptionally powerful case." The renewed application was refused. (The judgment spells the farm "Scovensten Park"; the BBC and other reports use Scoveston.)
In April 2023, when Cooper was 78, the Criminal Cases Review Commission confirmed it had received an application from him to review his convictions. The CCRC is the independent body that investigates possible miscarriages of justice in England, Wales and Northern Ireland, and it can refer a case back to the Court of Appeal only if there is a real possibility the conviction will be overturned, usually because of new evidence or new scientific developments. Dyfed-Powys Police said it would comply with its obligations in any judicial process but would not comment on the application. The grounds have not been made public.
The Pembrokeshire Herald, which has followed the application closely, reported that the CCRC confirmed it had received two applications concerning Cooper, that the review formally began in February 2024, and that the submission ran to more than a thousand pages. The paper has also published its own investigation into the handling of exhibits in the original inquiries. It reported incomplete exhibit logs, items from different cases stored together, and a flood, not previously disclosed, in an area where forensic material was stored. The Herald itself states that these issues "do not establish that Cooper was wrongly convicted," that the prosecution case was substantial and that the convictions stand.
On August 6, 2026, the Herald reported that the CCRC had confirmed both applications remained under review, that no decision had been made in either, and that both were now classed as "long-running," meaning under review for more than two years. A CCRC press officer said the commission would make a public announcement if either led to a referral. On October 1, 2026, Sky announced a three-part documentary series in which two Pembrokeshire residents, the journalist Andy Chandler and the legal assistant Hayley Wood, say they found material from Cooper's original defense that they believe raises new questions about his convictions and points to other possible suspects. Sky said the police remain confident they convicted the right man.
As of the August 6, 2026 Pembrokeshire Herald report, Cooper, then 81, was serving his whole life order and had not been released. His convictions stand. The Court of Appeal refused him leave to appeal in 2012, and his two applications to the CCRC were still under review with no decision. The October 1, 2026 announcement of Sky's documentary said the CCRC was still reviewing material in the case. Cooper continues to deny the murders.
After the verdict, police and others raised the question of whether Cooper had committed other crimes. None of these has led to a charge, and they are suspicions only.
Florence Evans, known as Flo, a widow in her seventies, was found dead, fully clothed, in her bath in 1989, soon after the Dixon murders. The BBC placed her home at Rosemarket; the Herald says Jordanston. An inquest found no suspicious circumstances, but her family never accepted that it was an accident. Cooper and his wife knew her and visited her, and he did odd jobs for her. Cooper himself mentioned her in his evidence. Steve Wilkins said after the trial that there was "connectivity" between them but "nothing concrete" linking Cooper to other offenses, and that he would talk to her family first about whether to look at her death again. Dyfed-Powys Police said in 2021 that it would examine specific new information but would not reinvestigate "on speculation alone."
In June 2011 South Wales Police said it had discussed with Ottawa detectives whether there was any connection to the unsolved 1993 shooting of Harry and Megan Tooze at their farm in Llanharry, near Bridgend. It said there were no plans to link the investigations. In September 2011 a forensic psychologist, Dr. Clive Sims, told the BBC Welsh-language program Taro Naw that the 1976 deaths of an elderly brother and sister, Griff and Patti Thomas, at Llangolman, where an inquest returned a verdict of manslaughter for Patti Thomas and an open verdict for her brother, should be reopened, and that Cooper could be a suspect. That is one expert's view; no court has examined it.
The case was dramatized by ITV as The Pembrokeshire Murders, shown on three nights in January 2021, with Luke Evans as Steve Wilkins and Keith Allen as Cooper. A companion documentary, The Pembrokeshire Murders: Catching the Game Show Killer, followed on BritBox. Allen told the Pembrokeshire Herald that his way into the character was the way Cooper said "scuba diving" in the Bullseye clip.
For Pembrokeshire, the killings changed how people lived for years. A Herald writer who started secondary school in Milford Haven in 1996 recalled being warned to stay out of Mount Woods after the attack on the teenagers. The Daily Post wrote at the end of the trial that the Dixon murders had made people from outside Wales think twice about holidaying there. The case is also cited as an example of cold-case forensic review: much of the evidence that convicted Cooper had been in police storage since 1998, and it was new techniques, applied to old exhibits, that tied it to the murders.
September 3, 1944: John William Cooper born in Milford Haven (Pembrokeshire Herald).
1966: Marries Patricia.
1978: Wins a spot-the-ball prize while working at the Gulf refinery.
About 1983: Begins burglaries, according to police.
December 22, 1985: Richard and Helen Thomas shot at Scoveston Park; the house is set on fire.
1989: Cooper appears on Bullseye (one or two months before the Dixon murders, by differing accounts).
June 29, 1989: Peter and Gwenda Dixon last seen leaving their tent at Howelston; they are shot on the coast path near Little Haven.
July 5, 1989: Their bodies are found. July 10: artist's impression of the cash card user released.
March 6, 1996: Five teenagers held at gunpoint near the Mount Estate, Milford Haven; two girls sexually assaulted.
November 1996: Armed robbery at Sardis; shotgun and other items recovered from hedgerows.
December 2, 1997: BBC Crimewatch reconstruction of the Dixon murders.
January 21, 1998: Cooper charged in Operation Huntsman.
December 10, 1998: Sentenced to 16 years for 30 burglaries and the Sardis robbery.
January 2000: Appeal against three Huntsman convictions dismissed.
February 2006: Operation Ottawa formed.
November 8, 2007: Ottawa press conference and renewed appeal.
June 2008: Cooper interviewed in prison custody over four days at Ammanford; denies the murders.
Early 2009: Released on license.
April 23, 2009: First call from LGC Forensics about significant findings.
May 13-15, 2009: Arrested, charged and remanded.
December 17, 2010: Court of Appeal rules he may contest the Huntsman convictions before the new jury.
March 21, 2011: Trial opens at Swansea Crown Court.
May 26, 2011: Convicted on all counts; life with a whole life order.
November 1, 2012: Court of Appeal refuses leave to appeal.
January 2021: ITV drama The Pembrokeshire Murders broadcast.
April 2023: CCRC confirms receipt of his application.
February 2024: CCRC review formally begins (Pembrokeshire Herald).
August 6, 2026: Herald reports both CCRC applications still under review, now "long-running," no decision.
October 1, 2026: Sky announces a documentary series re-examining the case; the CCRC review is described as continuing.