Gardaí believe the man shot dead in his home in Co Wicklow on Wednesday night may have invited the killer into his house.
Detectives discovered no indication of a break-in at the home of father-of-one Vincent O'Brien (53) at Kilbride Grove, suggesting the victim knew his killer and may even have spoken to him before the shooting.
Mr O'Brien was known to the Garda as a small-time drug-dealer. Among the possible motives being investigated is that the murder was a revenge killing for a recent assault on a more senior criminal figure in the area.
The murder follows renewed Opposition calls this week for the Government to do more to combat gun-related crime in the capital. Earlier this week, the Garda issued a statement saying Operation Anvil, its three-month-old clampdown on gangland activity in Dublin, was not being wound down despite reports to the contrary.
A young man wearing a hooded top and a baseball cap was seen running from the scene shortly after 10.30pm. Gardaí believe he left the estate via a pedestrian exit on to Killarney Road. Mr O'Brien was shot at least once in the head and several times in the body as he sat down to eat a takeaway meal. Neighbours said they heard four to five shots coming from the house.
A family living next door said they had thought the noise was a television falling off its bracket. A teenage member of the household was sent inside and discovered Mr O'Brien's body slouched across the sitting-room couch.
Other neighbours arrived at the scene and attempted to stem the flow of blood from the bullet wounds in the man's head and body. Mr O'Brien was later taken by ambulance to St Columcille's Hospital, Loughlinstown, where he was pronounced dead.
It was unclear yesterday when a postmortem on the body would take place. Gardaí were waiting to hear whether State Pathologist Prof Marie Cassidy would travel back from London after giving evidence in the Georgina Eager murder trial.
Supt Philip Moynihan of Bray Garda station said they had "very scant information" on the assailant but appealed for witnesses who saw anyone "who shouldn't have been in the area between 10.30pm and 10.45pm to come forward to speak to us".
No murder weapon has been discovered, but the Garda forensic unit has begun a search of the locality, while other officers are conducting house-to-house inquiries. Detectives believe there is an outside chance of the getaway being caught on a private CCTV camera, installed on a neighbouring home.
Neighbours said yesterday they caught no sight of the gunman but recalled hearing between four to five shots. "I thought it was someone drilling a hole," said one woman.
Mr O'Brien had been living alone in the house formerly occupied by a sister and her children. He was commonly seen by neighbours walking his German Shepherd dogs or driving his BMW 5-series in and out of the estate, near Ardmore Studios.
John Brady, a local Sinn Féin town councillor, who is also chairman of the local residents association, said it was considered to be "one of the better local authority estates in Wicklow".
Anyone with information can contact the Garda in Bray at 01-666 5300.
