The landlords of the pub, the Stonehaven Lounge and Market House Bar, also run the Stonehaven B&B where the couple were staying.
They were named locally last night as John Deegan from the Ballycumber area in Co Offaly and Deirdre Keegan from Naas in Co Kildare. Gardaí believe the couple were separated from other people but in a relationship together.
A member of the Clerkin family, which owns the B&B on Centaur St, is believed to have found the bodies at about 1.30pm yesterday.
Gardaí confirmed that both victims appeared to have shotgun wounds.
Gardaí are speaking to people who were in the pub on Sunday to see if anyone noticed anything about the man and woman that might help explain the tragedy.
Gardaí want to know if the couple, in their 50s, had a row while in the pub. It is understood they had been at the B&B from Friday.
Detectives suspect that, some time after they went back to the small, terraced B&B, the man shot the woman before turning the gun on himself. A shotgun, understood to be legally held, was found beside him. It will be sent for ballistic and forensic examination.
Supt Gerry Redmond confirmed the man was found downstairs in the B&B while the woman was found upstairs. He said it was too early to speculate on how long the bodies may have lain before being found at 1.30pm.
Garda sources said there was nothing to indicate a third person was involved.
The couple were last seen at about 10pm when they left the pub. It is understood the B&B, which has three bedrooms, was unoccupied apart from themselves.
Staff from the pub and B&B checked on the couple yesterday and discovered the man’s body. They immediately rang gardaí, who sealed off the area, pending the arrival of the technical bureau from Garda Headquarters and deputy state pathologist Michael Curtis.
Dr Curtis carried out a preliminary autopsy at the scene, with a full autopsy expected to take place this morning at Naas General Hospital. A medical examination will confirm whether the man’s wounds were self-inflicted.
One local, Kevin Coakley, said the couple were having a drink in the lounge on Sunday evening and that he saw them on Saturday. “I just got a quick glance at them,” he said. “It’s very sad for their families, the ones who are left behind.”
The Clerkin family did not want to comment.
Local councillor Walter Lacey said nobody could remember a similar killing in the area in the past. “It’s only when something like this hits your own town that you see the reality of it, and it has caused great shock in the community and among the people of Carlow,” he said.
People with information can ring Carlow Garda Station at 059 913 6620, the Confidential Line 1800 666 111, or any Garda station.
Ireland’s last murder-suicide also occurred in Carlow, when Michael Jordan, 51, shot dead his brother-in-law and neighbour George Rothwell, 71, near Bagenalstown, Co Carlow, before shooting himself.