Alexander Lewis-Ranwell has been charged with the murder of three elderly men in Exeter, Devon and Cornwall Police said.
Ranwell, 27, from Croyde, Braunton, is charged with the murder of Anthony Payne, 80, and 84-year-old twin brothers, Richard and Roger Carter.
Post-mortem examinations have confirmed that all three victims sustained serious head injuries.
He has also been charged with two counts of causing grievous bodily harm with intent and will appear at Exeter Magistrates’ Court on Saturday.
Detective Chief Inspector, Roy Linden, deputy head of major crime, said: “I would like to start by thanking everyone who has supported this investigation.
“Given this is now subject to formal court proceedings, we would remind everyone that Contempt of Court rules apply. It is therefore essential that no-one speculates about the investigation, particularly on social media. It is essential that we maintain the fairness and integrity of the court process.”
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.
Superintendent Matt Lawler, local policing commander for Exeter, East and Mid Devon, said: “All of our thoughts remain with the family and friends of the victims.
“You’ll continue to see officers on foot patrol, speaking to residents, and conducting investigative work at the two addresses in the city over the coming days.
“We are grateful for the messages of support that communities in and around Exeter have been expressing in recent days. We would like to sincerely thank local residents, our partner agencies and local councillors for their understanding and co-operation.”