Detectives investigating the fatal shooting of a father and son in two Cambridgeshire villages are waiting to see if a gun recovered in the Midlands was the firearm used in both killings. Police believe a dispute between a “close network of people” – mostly likely over a child custody battle – ended in violence with the double shooting. Three people have been arrested on suspicion of conspiracy to murder. The victims were named locally as Gary Dunmore and his son Josh Dunmore. The men were killed in two villages six miles apart on Wednesday evening, both in targeted attacks inside their homes, with multiple shots fired at both scenes, police said. Detectives have established that a shotgun that was found a three-hour drive away in Worcester – in the vehicle of a 66-year-old man who was arrested by armed police – was legally owned. Ammunition was also recovered. Officers were first called to reports of gunshots at a property in Bluntisham just after 9pm on Wednesday. They arrived to find the body of a 32-year-old man with a gunshot wound. At 9.37pm, police received a call from a person in nearby Sutton, again reporting hearing gunshots. The body of a 57-year-old man was found at a property there with gunshot wounds. DCS Jon Hutchinson said the victims were father and son. He said: “Working with local residents and family members, we quite quickly established that the two victims were related and they were father and son.” Hutchinson said the “primary line of investigation” was that the incident related to a “familial issue”. “It’s been widely reported in the media that this may relate to a custody battle,” he said. “I can confirm that is an active line of inquiry for us.” Police said they were not in a position to name either victim as formal identification had not been carried out. A 27-year-old man and a 33-year-old woman, who police said were from the local area, were arrested at a hotel just outside Cambridge. The 66-year-old man was arrested by armed officers on a motorway in the Worcester area. Police believe he was heading for the West Country and had recently moved to Cambridgeshire. “Following his arrest, his vehicle was searched and I can confirm we have recovered a firearm,” Hutchinson said. The properties, in Meridian Close, Bluntisham, and The Row, Sutton, were cordoned off and police officers remained at the scenes. One of the tributes left in Bluntisham said: “Josh, you shined such a bright light over everyone around you.” Neighbours near two semi-detached houses sealed off in Sutton described hearing gunshots and seeing armed police arrive shortly afterwards. Gordon Murray, 62, a support engineer who watched events unfold from his window, saw police cars arrive and armed police shouting on Wednesday evening. “I saw the police cars racing down here,” he said. “There was a lot of shouting. I thought it was an altercation or something. Then I saw the armed police. They were shouting something to the homeowners. That was it. I stood in the window watching.” Forensic officers in white suits worked at the scene on Thursday morning, with two bunches of flowers left on the drive. DI Mark Butler, from the major crime unit, said: “We have launched two linked murder investigations following the shootings of two men at separate properties in the county. These events will be shocking to local people and there will be understandable concerns within local communities; however, we are treating the attacks as targeted and there is no wider risk to the general public. “There will be an increased police presence in the areas concerned today and officers and scenes-of-crime officers will be at the scenes throughout the day. Our thoughts also go out to the family and friends of the victims. Specially trained officers are in touch with them and they are helping our investigation. “Detectives are now beginning inquiries into how these events unfolded and we are appealing to anyone who was in either area and saw anyone acting suspiciously or a white Peugeot 208. Any information, no matter how insignificant it may seem, could be very important to our investigation.” Murray said officers had asked him whether he had CCTV footage, and when he looked at it he saw that a white car had made two passes, and on the second pass the car stopped and someone opened the boot. Anyone with information is asked to call police on 101 quoting Operation Scan.