Analysis:A split between factions has escalated into bloody warfare, suggesting things may get worse before they get better, writes John Downes
The roots of the current gangland feud were sown in 2000, when gardaí seized more than €1 million worth of ecstasy and cocaine in Dublin city centre.
This prompted a split between different factions of a southside Dublin gang dealing in drugs, amid intense suspicion about who, if anybody, had tipped off the gardaí.
Declan Gavin, a 21-year-old drug dealer from Drimnagh, was the first to be killed, after he was fatally stabbed at a bus stop near Crumlin shopping centre in August 2001.
Other murders soon followed on both sides. One victim was 18-year-old Joseph Rattigan, who was shot in the head while walking in Crumlin.
He was suspected of being involved in the murder of Gavin.
But the past year has seen the feud escalate considerably, leading to the deaths of Noel Roche's brother, John, in March, and more recently the shootings of Gavin Byrne and Darren Geoghegan last Sunday.
As the macabre roll call of those who have been killed in this increasingly vicious and bloody gangland feud suggests, things may get worse before they get better.
Nevertheless, Chief Supt Peter Maguire from Santry Garda station could be forgiven for having particular sympathy for the Roche family this morning.
Indeed, it was not surprising to hear one of the State's most experienced detectives last night calling for anybody with information on Noel Roche's death to come forward.
He knows only too well how important it is to encourage all sides to overcome the climate of intense fear and paranoia. This will be particularly pronounced in Dublin's criminal underworld this morning.
Somewhere in the city, there is likely to be an injured man living in fear of his life.
The driver of the car in which Noel Roche was travelling as a front-seat passenger when he was shot and killed on Clontarf Road on Tuesday night staggered away from the vehicle.
He has still not been found by gardaí, or responded to appeals to come forward.