Detectives are continuing to hold a man on suspicion of murder after three elderly men were violently killed in their homes just a mile apart.
The bodies of twins Dick and Roger Carter, 84, and Anthony Payne, 80, were found less than 24 hours apart in Exeter, Devon.
Post-mortem examinations have confirmed that all three victims sustained serious head injuries. Detective Chief Inspector Roy Linden said: “The investigations into these three incidents remain connected.
“Due to the serious head injuries sustained by all three victims and the presentation of the properties and the age of the victims, we are treating this as a single multiple murder investigation.”
A 27-year-old man arrested on Tuesday remains in custody at Heavitree police station in Exeter, while investigators work to establish how the victims and the suspect may be connected.
On Thursday it emerged the force had been granted an additional 36 hours to hold him, though during a press conference it emerged that officers are yet to interview him.
Detectives said they were not “actively” looking for anyone else in relation to the deaths, but locals were urged to check on elderly neighbours or relatives.
Lianne Hill, who lives near the Carters, said: “It’s a bit scary when it is so close to home.”
The ambulance service alerted police to Payne’s body at his terrace house in Bonhay Road at about 3pm on Monday.
And at 1pm the following day, officers went to the Carter brothers’ detached home in Cowick Lane after their bodies were found.
Police arrested the suspect hours later.
One woman who lives near the Carters said her mother had seen a “scruffy looking man carrying a tool bag” outside the elderly twins’ home just hours before their bodies were discovered.
The two murder scenes are just over a mile away from each other, but it is understood there are no links between the Carter brothers and Payne.
Despite media reports that an antique shotgun was found at the scene in Bonhay Road, forensic examinations have revealed the injuries sustained have not been connected to the use of a firearm.
Police urged anyone in the area of Bonhay Road and Cowick Lane between 8am on February 10 and 1pm on February 12 to come forward.
Superintendent Matt Lawler, the local policing commander for Exeter, East and Mid Devon, said: “Based on our current information we have yet to establish a clear connection between the parties involved.
“I know that this news will cause significant and understandable concern and is an unprecedented event in our city which has shocked us all.”
At Payne’s home, a handwritten note had been left on the front door which read: “Elderly man 80 years of age wants accommodation for himself and his pet cat. Any replies to 65 Bonhay Road.”
It was signed “AG Payne”.
Floral tributes were left to the Carter brothers, who had previously run an agricultural business called TrayCrop, outside their house.
Local shopkeeper Jim Wright told the BBC the brothers were “eccentric and reclusive” and that one of them would come into his shop regularly.
Wooden screens had been erected over the gates of the property.
One card said: “To Dick and Roger, will miss your conversations and drives to Sainsbury’s. RIP, Doris and Fred.”
Uniformed officers were also seen removing items from a wheelie bin in nearby Church Park Road and placing them in evidence bags.
Neighbours said the one of the items looked like a “flip flop or the sole of a shoe”.