IN 1989, Witney holidaymakers Peter and Gwenda Dixon, were shot dead on a camping holiday in Pembrokeshire.

It took 8,001 days for police to bring their killer John Cooper to justice when the gunman was caged for life with no chance of parole in 2011.

The case was finally broken when crucial new evidence linked the farm labourer to the crimes.

In the end, police produced 30,707 documents and conducted 1,603 interviews to catch the murderer.

Now the detective who caught Cooper and the journalist who followed the story have written a book The Pembrokeshire Murders: Catching the Bullseye Killer.

Former Det Ch Supt Steve Wilkins, who led the cold case investigation from 2005 onwards said:

" AT THE time of both double murders, I was a serving police officer in Cheshire. I took a particular interest because I had lived in Pembrokeshire prior to joining the police and still had family in the area where the crimes took place.

There was a great deal of speculation among local people and the discovery of an IRA arms stash near to the scene of the murders of Peter and Gwenda Dixon appeared to provide a convenient solution in some people’s minds.

I transferred to Dyfed Powys Police in 1992 and progressed my career through the CID.

The Pembrokeshire offences were like a troublesome relative. No one really wanted to talk about them and they remained undetected.

The area of north Pembrokeshire was plagued with a large number of house burglaries and armed robberies where lone females were attacked in their homes by a single, violent offender. In 1996, there were two particularly violent attacks.

The first involved five children who were attacked at gunpoint. One of the girls was raped in a field near to the scene of the double murders of Richard and Helen Thomas in 1985 and the second was an armed robbery on a lone female in her home in the same vicinity.

During the second attack, the offender fled the scene after an alarm was activated.

As he did so, he abandoned items of clothing and a double-barrelled sawn-off shotgun in the hedgerows.

These were recovered by police and soon after John William Cooper was arrested for this robbery and a string of burglaries.

Property from a large number of offences was found in and around his home. This included over 500 keys recovered from his cesspit, some of which fitted the doors of the houses he attacked. Buried under a duck run, the police also found another shotgun carefully preserved in oil and rags.

Cooper was convicted and received a 16-year sentence, but the two double murders and attack on the children remained undetected.

In 2005, I was a Detective Superintendent in charge of crime operations and it was my view that we needed to review all of the Pembrokeshire serious crime.

It was a massive task. There were five computerised incident rooms and over 40,000 exhibits. This represented over two million pieces of paper.

I chose to undertake a forensic review of all the exhibits and this included the meticulous forensic recovery of them from where they had been stored. I needed a special team and handpicked those detectives and officers who I knew had the necessary skills and attention to detail that the task required.

Cooper was a dangerous man who was due for parole.

I had been told that if it was him, he was likely to kill again. I named Cooper as my suspect. A chance conversation with an ITV presenter, Jonathan Hill, started a close and fruitful relationship. Little did we know that in fact he held a vital piece of identification evidence when Cooper was on the popular game show Bullseye weeks before he killed the Dixons.

I had also become very close to the Dixon family. They are a remarkable family who have had to deal with the terrible loss of Peter and Gwenda and the media frenzy that followed.

It was almost three years before we had our first forensic break when blood belonging to Peter Dixon was found on a pair of shorts recovered from Cooper. More quickly followed, including strong fibre links and bloodstains on the barrel of the shotgun used by Cooper during his robberies. This was the Dixons’ murder weapon.

Cooper was arrested for all of the offences. He was a calm, cool character who admitted nothing, but during his interviews he tried to cover his tracks with a web of lies.

The work carried out during the investigation meant we could easily pick holes in his stories. He had met his match. Cooper was convicted of four murders, five robberies and rape, and sentenced to life."

ITV journalist Jonathan Hill who worked on the story said:

"IN SOME ways, it could be said I began writing this book in my head when I was 20 years old. Back in 1990, I was student and went camping with friends on the beautiful Pembrokeshire coast.

It was June, exactly a year after Oxfordshire couple Peter and Gwenda Dixon had been blasted to death while holidaying in the area.

I remembered all the publicity at the time and now, exactly 12 months on, with the murders still unsolved, there was a large police presence in the area as they tried to jog people’s memories and find potential witnesses. I remember being fascinated by this baffling case.

My in-laws lived in the area and over the years we discussed the case many times. They admitted that at the time of the murders they had considered leaving their retirement home and moving away, such was the fear in this idyllic part of west Wales.

It seemed so strange that two people could be murdered on the coastal path in broad daylight. What could possibly be the motive?

Weird and wonderful theories began to emerge involving the IRA and arms dumps, but all came to nothing.

The case stayed with me as I began my career in journalism, as did my interest in crime reporting.

In 2007 I was presenting a programme called Crime Secrets on ITV and we were looking at so-called cold cases. I was extremely keen that we investigate the murders of the Dixons and another two murders, which happened four years earlier just a few miles away.

On the face of it, there were clear similarities between the two cases, although the police had never officially linked them.

Richard and Helen Thomas were brother and sister and lived as Scoveston Park, an isolated Georgian manor house on the outskirts of Milford Haven. Just before Christmas, they were blasted to death and the house set on fire.

Again, it seemed an almost incredible event to have happened in rural Pembrokeshire.

Both cases remained unsolved, so we decided to begin preparations to make a programme.

I could hardly believe that I was getting the chance to investigate the murders, which had captured my imagination 17 years earlier.

What happened next was even more extraordinary.

In mid 2007, I arranged a meeting with Dyfed Powys Police, who up until now had refused to discuss the case. I was shown into a room with Det Ch Supt Steve Wilkins. I explained to him that we would very much like the force to take part in the film, but if they declined we could still make it without them.

His face changed and he closed the door. He then revealed to me that the murders were now the subject of a review and that any publicity could seriously damage the investigation.

If I agreed to keep the story quiet, then he would give me the exclusive when it was time to go public.

It was a huge leap of faith on his part and the beginning of a professional relationship that would endure many twists and turns. The biggest twist was yet to come.

The police knew that the main suspect John Cooper had appeared on the ITV 1980s game show Bullseye, but they didn’t know when. I began to make enquiries and we discovered that Cooper had appeared exactly a month to the day before he murdered the Dixons.

The police were delighted because it meant that they had moving footage of Cooper at the time of the murders and they already had an artist’s impression of a man seen using Peter Dixon’s cashcard after the killing. When we compared the images, there was a compelling match. It’s not often that a serial killer appears on a game show.

The Bullseye film would go on to be played to the jury who convicted Cooper of the double murders.

I have spent the last six years working on both the film and this book and I am still impressed by the skill and dedication of the small team of detectives who brought Cooper to justice after more than 20 years."


Welsh camping holiday that ended in horror

AT THE time of their murders, Peter Dixon was 51 years old and his wife 52. They lived in Oxfordshire and regularly spent time in the summer at Howelston Farm Caravan Site in Little Haven.

The couple arrived at the caravan site on June 19, 1989.

They were last seen alive by fellow campers at about 9.30am on June 29, approximately an hour before they were murdered, walking out of the caravan site in the direction of the coastal path.

At about 10.30am, several witnesses heard gunshots in the vicinity of the coastal path.

Five shots were heard, comprising two sets of two followed by one final shot.

The evidence of the Home Office pathologist, Bernard Knight, confirmed that Peter Dixon was shot three times, with his hands tied behind him, and Gwenda Dixon twice in an execution-style killing. They were killed with a sawn-off shotgun fired at close range. Their bodies were found on July 5 about 600 yards from the caravan site, in a clearing, in thick vegetation between the coastal path and the edge of the cliff.

The bodies had been hidden by branches and uprooted plants.

Peter Dixon’s NatWest cash card and wedding ring were missing.

Gwenda Dixon’s body was naked from the waist down.

Inquiries revealed that Mr Dixon’s cash card was used four times after his death.

Witnesses helped create an artist’s impression of a man seen using the card to withdraw cash.

Video evidence of John Cooper appearing on the TV gameshow Bullseye, filmed just before the murders, bore an uncanny resemblance to the picture.


  • 1985 – John Cooper shoots to death millionaire Richard Thomas, 58, and his sister Helen, 56, after being caught breaking into their home near Milford Haven. 
  • June 19, 1989: Peter and Gwenda Dixon, 51 and 52, load up their car and head from their home in Moorland Road, Witney, to Little Haven in west Wales for a fortnight of walking and bird-watching.
  • June 27: Joined by their son Tim, the family tour nearby cathedral city St David’s. Tim returns home that night.
  • June 29: The Dixons are seen to leave the campsite at about 9.30am and head for a wooded section of the coastal path in the hope of glimpsing rare peregrine falcons. It is the last time they are seen alive.
  • July 2: Tim Dixon reports to police that his parents have not returned from their holiday. Officers search the campsite and find the Dixons’ pitch exactly as they left it.
  • July 5: At 3.30pm, police with sniffer dogs find the couple’s bodies in undergrowth near the cliff walk. Mr Dixon was found with his hands bound behind his back. His wife was lying beside him.
  • June 1990: Police make another appeal on the anniversary of the couple’s death but the trail goes cold.
  • 1996: Cooper holds a group of teenagers at gunpoint as they played in a field. He rapes one and sexually assaults another.
  • 1997: The BBC broadcasts a special Crimewatch programme appealing for information about the Dixon murders and police receive more than 400 calls.
  • 1998: Cooper arrested and jailed for 16 years for 30 burglaries and the violent robbery of retired school teacher Sheila Clark at her home in the village of Sardis.
  • 2006: Operation Ottawa launched to look into unsolved crimes in Pembrokeshire.
  • 2007: Cold case review launched into Dixons’ murder. Modern forensic techniques begin to link Cooper and his shotgun to the murders and sex attacks.
  • 2008: Cooper interviewed in prison over four days.
  • 2009: Forensic evidence leads to Cooper being charged with four murders, sexual assault and five attempted robberies.
  • 2011: John Cooper jailed for life with no hope of parole.
  • Oct 2012: Cooper appeals Dixons’ murder convictions.
  • Nov 2012: Judge rejects appeal.