A man who shot a father and son dead had a “shortlist of people” he intended to murder, a court has heard.
Gary Dunmore, 57, and Josh Dunmore, 32, died at separate properties in two Cambridgeshire villages in March.
When arrested hours later, Stephen Alderton told police “sometimes you have to do what you have to do even if it’s wrong in the eyes of the law”.
The sentencing of the 67-year-old – who admitted to the murders – has been adjourned until Monday.
Cambridge Crown Court was told the killings came two days after a family court hearing.
Josh Dunmore, the former partner of Alderton’s daughter, was found dead at his home in Bluntisham, while six miles away his father was found dead at his home in Sutton on 29 March.
The court heard Alderton, of no fixed address, had written in a telephone message last year: “I’ve a shortlist of people I intend to murder.”
The prosecutor said Alderton had a shotgun licence and lawfully held a Beretta shotgun which was used in both killings.
Alderton’s wife died in 2020 and at the time he was living in a motorhome on a site in Willingham, the court was told.
Police said Josh Dunmore was shot at 21:09 BST and Gary Dunmore was shot 31 minutes later.
The prosecutor said it was likely Alderton knocked on Josh Dunmore’s door and shot him “twice at close range” when he opened it, in the left chest and the right side of his head, which would have been “rapidly fatal”.
Gary Dunmore was also shot at close range, with three of four shots hitting him, the prosecutor said.
“The defendant had to reload as two shots can be fired from the shotgun,” he said.
The prosecutor said Alderton was “rapidly identified” as a suspect.
His motorhome was picked out on automatic number plate recognition cameras and he was stopped by armed officers on the M5 near Worcester at about 01:30 that same night.
‘Calm manner’
Alderton was the only occupant and “he volunteered that the shotgun was in the motorhome which it was”, the prosecutor said.
Some family members who packed into the courtroom wept as details of the case were read, while more listened remotely from another room within the building.
Earlier, judge Mark Bishop asked for the case to be dealt with in a “calm manner” and stated: “I don’t want any hard staring of the defendant by the family members.”
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