The true story behind 24 Hours in Police Custody: A Family Vendetta

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The true story behind 24 Hours in Police Custody: A Family Vendetta

The murders of Gary and Josh Dunmore in March 2023 are the subject of a 24 Hours in Police Custody special, exploring the events and arrest of Stephen Alderton.

Roxy Simons

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Entertainment Editor

Updated

Tue, December 9, 2025 at 3:40 PM UTC

3 min read

24 Hours in Police Custody: A Family Vendetta (Channel 4)
24 Hours in Police Custody: A Family Vendetta examines the murders of Gary and Josh Dunmore by Stephen Alderton, pictured. (Channel 4)

24 Hours in Police Custody has released a new special focused on the murders of father and son Gary and Josh Dunmore in March 2023.

The two-part special explores the case in detail, including the arrest of Stephen Alderton, who was charged with the murders. In the documentary, viewers are given insight into the case from the first emergency call to the investigation into the shooting, Alderton's arrest and interrogation by police.

For those curious to learn more, here is what you need to know about the case.

The murders of Gary and Josh Dunmore

24 Hours in Police Custody: A Family Vendetta (Channel 4)
A still from 24 Hours in Police Custody: A Family Vendetta. (Channel 4)

On the evening of 29 March 2023, Josh Dunmore was shot twice at his home in Meridian Close, Bluntisham. He was the former partner of Alderton's daughter, with whom he had a son. 30 minutes later, his father, Gary Dunmore, was shot and killed at his home in The Row, Sutton.

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At the time, police called the murders "targeted" attacks, and it was later revealed in court that the killings came two days after a family court hearing.

Following the killings, Alderton was "rapidly identified" as the suspect, prosecutor Peter Gair said in court, per the BBC. Alderton was living in a motorhome, and the vehicle was found by a number plate recognition camera, which led police to him.

Flowers and messages left for the victim at the scene in Meridian Close, Bluntisham, Cambridgeshire. Police found the body of the 32-year-old, named locally as Josh Dunmore, with a gunshot wound on Wednesday evening. They were later called to a second property in in Sutton, where they found the body of a 57-year-old, named locally as Josh's father Gary Dunmore, who had also died from gunshot wounds. The deaths of both men are being treated as murder and three men have been arrested by Cambridgeshire Police. Picture date: Friday March 31, 2023. (Photo by Sam Russell/PA Images via Getty Images)
Josh Dunmore and his father Gary Dunmore were murdered at their respective homes in Cambridgeshire in March 2023. (Getty)

He was stopped by armed officers on the M5 near Worcester the same night as the murders. When he was arrested, he told police that “sometimes you have to do what you have to do even if it’s wrong in the eyes of the law”.

During the investigation, police found Alderton had written in a message that he had "a shortlist of people I intend to murder."

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After his arrest, Alderton pleaded guilty to two counts of murder.

What happened to Stephen Alderton?

24 Hours in Police Custody: A Family Vendetta (Channel 4)
Stephen Alderton pictured in 24 Hours in Police Custody: A Family Vendetta, he was sentenced to life imprisonment. (Channel 4)

During the case, it was revealed that Alderton committed the murders over his "distorted beliefs" about family court proceedings involving his grandson, "following what was an interim and not final hearing on 27 March".

It was confirmed that Alderton's daughter, Samantha Stephen, had requested to "move their seven-year-old child from the jurisdiction of the court by emigrating to the USA." After her split from Dunmore, she married Paul Stephen, a member of the US Air Force who was set to be redeployed to the US.

Alderton's daughter had "sought permission of the family court, and Joshua opposed the application".

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Adrian Langdale KC shared a letter from Alderton to the court, which, per the BBC, said: "If I could turn back time, I would. I regret there are not enough words of remorse I can offer to the families affected by this crime."

The accused added that he was "not the person that this conflict and the family courts have driven me to become", and wrote: "I've never been a violent person, I do not have a criminal record. I've been a respectable, law-abiding citizen all my life.

"What happened to me on 29 March, I do not know."

Alderton was sentenced to life imprisonment with a minimum term of 25 years. After delivering the sentence, the judge in the case told Alderton: "You took the decision to take the law into your own hands and end the lives of two innocent men."

In January 2024, Alderton's sentence was raised by the Court of Appeal to a minimum of 30 years served in prison.

24 Hours in Police Custody: A Family Vendetta continues at 9pm on Channel 4.

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