top of page
  • Writer's pictureThe True Crime Edition

The Pembrokeshire Murders

The investigations spanned 25 years and John Cooper was finally caught with the help of a quiz show.

John Cooper (right) on Bullseye via

Born on the 3rd of September 1944, John Cooper lived in Milford Haven, a small town in Pembrokeshire, Wales, where he worked as a farm labourer. He was a keen fisherman and knew the local area well, spending most of his free time outdoors.

In 1966, he married Patricia, and the couple had two children, a girl and a boy. In 1978, Cooper won a new car and £90,000 in a competition. He set up a small farm, but due to his gambling habit, alcoholism and poor financial choices, the money soon disappeared. Shortly after, Cooper turned to burglary.

He was a prolific thief in his late teens, and he knew how to get in and out of homes. In his youth, he was charged with stealing a car and assaulting a police officer. In total, he committed around 30 robberies and violent assaults on the unsuspecting.

To residents of Milford Haven, John Cooper was a likeable man, but he took his aggression out on his son behind closed doors. In the ITV documentary, Real Crime with Mark Austin, Andrew said that while fishing with his father, the 11-year-old was hit in the face and pushed to the floor. Cooper then pointed a gun at his son and told him that he was worthless and his family didn’t want him anymore. He pulled the trigger, but the gun was empty.

The abuse was continuous, and Andrew, now an adult, has 12 screws holding his spine in place from being punched so viciously in the back when he was a child.

Richard and Helen

Three days before Christmas of 1985, Cooper broke into a large farmhouse in Scoveston Park, near to Milford Haven. The home belonged to Richard and Helen Thomas, and Cooper likely knew that Helen, who was in her fifties, was alone in the three-storey home.

Scoveston Park via

While he was robbing the house, Richard returned home and surprised Cooper. In return, he shot Richard in the stomach and head. Helen had been tied up and shot in the head. He then poured diesel all over the house before setting it on fire to cover any tracks he left behind.

Richard and Helen Thomas via walesonline

An investigation was carried out, but police believed it was a robbery that had gone wrong. Nevertheless, a door-to-door enquiry was carried out, which included the Cooper family’s home.

They all had an alibi; they were all in the home together when the robbery and fire took place. Cooper told his son to lie to the police, who, as a child, thought nothing of it. Cooper was never suspected as the murderer.


On the 28th of May 1989, Cooper was a contestant on British favourite, Bullseye, a televised darts quiz. He claimed on the show that he was a keen scuba diver due to the coastline around Milford Haven. He missed out on the top prize of the night.

John Cooper on Bullseye via YouTube

Three weeks later, he killed two more people.

Peter and Gwenda

Peter and Gwenda Dixon were out walking on the Little Haven path, near the coastline. Their couple were in their fifties and had come to the region from Oxfordshire to enjoy the fresh air, as they had done for many years previously.

The community was quiet and friendly, with a picturesque shoreline that attracted hundreds of tourists every year.

On the last day of their holiday, the pair went for a short hike. They told nearby neighbours in the campsite that they were going for one final walk before they travelled home, but they were never seen alive again.

Half a mile from their camp, they entered a path surrounded by trees, where John Cooper was waiting for them. He brandished a sawn-off shotgun and told them to give him their money. During their capture, Peter gave Cooper his bank card and PIN, with which Cooper withdrew £300 from different ATMs around the local area later that day. He took Peter’s wedding ring and then shot them both in the face.

Peter and Gwenda Dixon via

Two days later, their son, Tim, reported them missing, and the police began their search. The hunt for the couple didn’t last long, and the police dogs found their bodies quickly. The violence used on the couple was unprecedented, and it became the largest murder enquiry Pembrokeshire had ever dealt with.

Shortly after discovering his parents’ bodies, Tim made a public statement and plea for information surrounding their murders. Witnesses came forward and gave police a description of a man they’d seen using an ATM in town that day.

The sketch of the man at the cashpoint via Real Crime with Mark Austin on ITV

Investigators interviewed 6,000 people, and one of them was John Cooper himself, who was working as a farm labourer again. The police had no reason to suspect Cooper at the time, as they didn’t know about his history of violence towards his family and others.

After 18 months of searching for the killer, the investigation had hit a standstill and resources were dispersed elsewhere in the police department.

Assault and robbery

In March 1996, Cooper robbed five people in one go. The teenagers were walking through a field as the sun set in Milford Haven when they saw a man walking straight towards them.

He was wearing a balaclava and fired a warning shot into the air with his gun. He then sexually assaulted two young girls and took money from the rest of the teens. No one was caught for the crimes.

The police knew very little about the suspect, but they were beginning to see a pattern within the 70 recent robberies in the area. They knew that the man wore a balaclava, he entered the property in the evening, and his weapon of choice was a sawn-off shotgun.

In November of the same year, Cooper was interrupted during a robbery and threw pieces of his gear into a nearby hedge when he fled. These objects included a gun and balaclava.

While searching the nearby area, police knocked on the door of one home to see if the residents had seen anything when they found the stolen property. It was John Cooper’s home.

Caught red-handed

The house was immediately searched, as was Cooper’s families’ homes around the area, and a substantial amount of stolen goods were discovered. He was found to be involved in almost 30 robberies and an additional armed robbery.

While in custody, he was questioned about the murders of Peter and Gwenda Dixon and Richard and Helen Thomas. He denied knowing anything about the killings, and police learned he would never admit to what he had done, so they began to search for evidence that would put him at the crime scenes.

John Cooper being arrested via Milford Mercury

In the late ‘90s, forensics was still infantile, and despite police efforts, they couldn’t find anything to link him to the four murders, but they could imprison him for the thefts. In 1998, John Cooper was sentenced to 14 years in prison for the robberies.

While in prison, police continued to build a case against Cooper. They carefully kept all the evidence from the four murders, knowing that one day they’d be able to find the killer.

Technology catches up

In 2006, the investigations were reopened. The advance in technology was going to make solving the cases much easier for police. Still, over the years, the amount of evidence amassed in the four murders and the rape and robbery of the teenagers had reached around 2 million exhibits and reports.

The police were sure that John Cooper was involved, but they had to find the truth about the three investigations, whatever the outcome. They needed to prioritise which pieces of evidence held the key to solving the cases.

Over the next few months, the police set up a team of officers who interviewed people in John Cooper’s life. They found out information from his family, primarily his son, Andrew, who had been subject to torment and abuse throughout his childhood.

Cooper had begun to rob houses for the money but also the thrill. He had become accustomed to the lifestyle given to him by the £90,000 win he had made in the ’70s and didn’t want to give that up.

In July 2008, investigators interviewed John Cooper for four days, who was about to be released for the robberies. They talked about his life and his work, and he began to open up to them. He spoke about the shotgun he used in the robberies and told them he was under the impression that the gun would be destroyed after the case had gone to court. But at the point of the interviews, it was still in evidence, and he seemed nervous about that prospect.

Police had the gun tested by the forensics team again, but John Cooper had been released after serving ten years in prison.

The investigative team tested the clothing worn by Cooper, which matched the sketch made by a witness. In April 2009, they found their evidence.

There was a 20-year-old drop of blood on Cooper’s shorts, and it belonged to Peter Dixon. From here, the evidence kept on coming.

The shorts had been restitched after purchase, and under the hemline, forensic investigators found DNA from the Dixons’ daughter, Julie. Cooper had stolen the shorts from Peter Dixon during the robbery and had kept them for over ten years.

Peter Dixon’s shorts via walesonline

There were fibres from the balaclava present in the underwear of one of Cooper’s teenage rape victims. Also, fibres were found in Peter Dixon’s stolen shorts that matched fibres found on Richard Thomas’ socks. He was still wearing the souvenirs he’d taken from his victims decades later.

Blood was eventually found on the shotgun, kept from Cooper’s original robbery conviction. The gun had been painted after the murders of Peter and Gwenda Dixon, and the blood underneath the thick black paint had been maintained.

Investigators didn’t want to leave anything to chance; they needed to get a conviction, so they began to look at the sketch made by the witness. The producers of Bullseye gave investigators a profile shot taken from the programme, and the resemblance was there. The time between filming the show and the murders was only a few weeks, and he looked exactly the same.

The sketch of the man at the cash point via


In May 2009, John Cooper was arrested for the four murders. He initially told police that the shorts stolen from Peter Dixon were bought for him by his wife many years earlier. He also said that his son, Andrew was the perpetrator, saying that he often borrowed his clothes.

Cooper was put on trial in March 2011 and was charged with the four murders of Peter and Gwenda Dixon, Richard and Helen Thomas, and the robbery, rape and sexual assault of the teenagers in Milford Haven.

The trial at Swansea Crown Court lasted nine weeks, and witnesses for the prosecution included John Cooper’s son, Andrew, and the two female teenagers who were sexually assaulted. The court was shown the vast amount of forensic evidence against the defendant and the photos of the faceless Peter and Helen Dixon. It took the jury three days to decide on a verdict; guilty of all charges and sentenced to life in prison.

John Cooper attempted to appeal his conviction later that year, but the Lord Chief Justice refused it;

“The application for leave to appeal against conviction was refused by a single judge. We agree with him. This renewed application will similarly be refused.”

It took 25 years to take John Cooper to court for the murders, but in the end, justice prevailed.


bottom of page