Forensic experts are examining the scene of last night's double murder in Kilcock, Co Kildare.
It is believed that up to three gunmen entered the house in the Rochford Estate at around 10.20pm.
A 31-year-old man, who had links to a Dublin drugs gang, was shot dead. A man in his 30s was also killed, but he has not yet been identified.
Two other men in the house were injured and are being treated in the Mater and Tallaght hospitals in Dublin for non-life threatening injuries.
Gardaí are now appealing for information on the getaway car and the route it took following the shooting.
The gunmen used at least two guns and did not have to force their way into the house.
Detectives say the house could have been under surveillance in the hours or days before the murders.
Gardaí have begun a double murder investigation.
An incident room has been set up at Leixlip Garda Station and gardaí are appealing for anyone with information to contact them on 01-6667800.