A widower who shot dead his daughter’s ex-partner and her ex-partner’s father over a family court case involving his grandson has been sentenced to life in prison with a minimum term of 25 years for their murders.
Stephen Alderton, 67, had written in previous text messages that he would “override any court decision” and that there was “always a plan B”, Cambridge Crown Court heard.
Prosecutor Peter Gair said former chartered quantity surveyor Alderton blasted the two men with his Beretta shotgun on March 29 this year, two days after a family court hearing.
The defendant, of no fixed address, pleaded guilty at an earlier hearing to the murders of Joshua Dunmore, 32, and his 57-year-old father Gary Dunmore.
The pair were found dead at their homes in villages six miles apart in Cambridgeshire, with Joshua Dunmore’s home in Bluntisham and his father’s in Sutton.
After Alderton was arrested hours later by armed officers on a motorway, 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”, Mr Gair said.
“We say it’s clear that the events were triggered by an ongoing family court case between this defendant’s daughter Samantha Stephen, nee Alderton, and her former partner Joshua Dunmore,” he said.
“This concerned a request to move their seven-year-old child from the jurisdiction of the court by emigrating to the USA.”
He said that Mrs Stephen and Mr Dunmore’s relationship ended shortly after their son was born and in 2020 she married her current partner, Paul Stephen.
Mr Gair said Mr Stephen, a US national, served with the US Air Force.
“He was due to be redeployed back to the USA,” said Mr Gair.
He said they “sought permission of the family court and Joshua opposed the application”.
“There was a hearing on March 27 2023 and it would appear (the child) wouldn’t be removed from the jurisdiction,” said Mr Gair.
Adrian Langdale KC, mitigating for Alderton, said Alderton’s wife died in December 2019.
Mr Gair said Alderton sold his home and was living at the time of the offences in a motorhome on a site in Willingham, Cambridgeshire.
Mr Gair said that Alderton was “rapidly identified” as a suspect after the shootings due to the family court case and sightings of the white Peugeot.
His motorhome was picked up by police using ANPR (automatic number plate recognition) cameras.
He was stopped by armed police from the West Mercia force on the M5 near Worcester at about 1.30am on March 30, police said.
Mr Langdale said the defendant wrote in a letter: “I’m not the person that this conflict and the family courts have driven me to become.
“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 March 29 I do not know.”
