A harrowing double murder that shocked two Cambridgeshire communities is set to be explored in depth in a forthcoming two-part special of the Channel 4 documentary series 24 Hours in Police Custody. The programme, titled A Family Vendetta, will air at 9pm on 8 and 9 December and follows detectives as they unravel the fatal events of 29 March 2023.
The episodes shadow DCI Katie Dounias and officers from the Bedfordshire, Cambridgeshire and Hertfordshire Major Crime Unit as they respond to the shootings of father and son Gary and Josh Dunmore, killed just over half an hour apart in their homes in Sutton and Bluntisham.
The investigation began when 32-year-old Josh Dunmore was found fatally shot in the hallway of his home in Meridian Close, Bluntisham.
Thirty-one minutes later, police were called to The Row in Sutton, where his father, 57-year-old Gary Dunmore, had also been shot dead.
The programme charts the urgent manhunt that followed, culminating in the dramatic arrest of gunman Stephen Alderton, then 67, who was stopped by armed officers on the M5 near Worcester in the early hours of the next morning.
As the documentary shows, detectives pieced together a tragic chain of events rooted in an ongoing family dispute and tensions surrounding court proceedings days earlier. Alderton later admitted two counts of murder and was jailed for life in June 2023.
His minimum term, originally set at 25 years, was increased to 30 years by the Court of Appeal in January 2024 following a referral by the Solicitor General.
DCI Dounias said the programme highlights the devastating consequences of Alderton’s “rash and brutal actions”, praising the courage of family members who chose to share their experiences on camera. “No sentence can repair the irreparable harm caused,” she said.
Solicitor General Robert Courts KC MP said the extended sentence sent a clear message about the seriousness with which such offences are treated, describing the killings as a “brutal” act that “ripped apart a family”.
24 Hours in Police Custody: A Family Vendetta will be broadcast on Channel 4 next Monday and Tuesday.
