Stephen Lynch may have been killed for saying the wrong thing.
The 32 year old died after being struck by a car in Tallaght on Thursday night.
Gardaí believe Stephen Lynch got involved in a verbal row with four men, who were travelling in a silver Ford Focus.
According to the Irish Independent, the group are believed to be the main suspects in the murder.
Sources close to the investigation say gardai are expected to arrest the gang of up to four men soon.
Mr Lynch was also kicked as he lay unconscious on the ground.
The driver then fled the scene on foot and is suspected of getting into another car.
Garda Superintendent Peter Duff said Mr Lynch was "not involved in any form of criminality".