Gardaí are working to establish a motive for this morning's shooting in Ballyfermot.
They're appealing for help in tracing the movements of the gunman who killed a man in his 50s at Croftwood Drive.
At 11 o'clock this morning the victim - who had recently returned to Ireland - was shot dead on his doorstep, after responding to a knock at the front door.
Members of his family were in the house at the time of the shooting.
Gardaí believe the gunman then drove a Blue Ford Fiesta to Le Fanu Drive and set fire to the vehicle before walking to Killeen Road.
Supt. Tony Twomey says it was there he got into silver Skoda Octavia.
Gardai say they're still trying to establish a motive for the murder and are appealing for witnesses to come forward.
