The brother of Gerry 'The Monk' Hutch was murdered in cold blood in a vicious retaliation to Friday's hotel shootout.
Edward Hutch, known locally as Neddie, was gunned down inside a house on Poplar Row in the north inner city just before 7.45pm.
A gang of four men burst into the house - through the window and front door - shooting Mr Hutch up to nine times.
A local source told the Herald that up to a dozen shots were fired at the scene.
Sources last night said that Mr Hutch was not a player in organised crime and was considered a "soft target".
The Christy Kinahan cartel are the chief suspects for the shocking revenge murder and the assassination is considered a major escalation of gang war that is spiralling out of control.
Mr Hutch was targeted because he was the brother of 'The Monk' and the uncle of Gary Hutch who was shot dead by the same gang in Spain last September. It is understood that he had worked as a taxi driver and had not been in serious trouble with the law for decades.
"He was a soft target. They only went after him because they know the pain it is going to cause his brother Gerry," a source said.
In a deadly cycle of tit-for-tat violence, associates of Gary murdered senior cartel member David Byrne in the Regency Hotel on Friday.
The Drumcondra shooting in turn led the cartel to declare that anyone connected to Gary or Gerry Hutch was a legitimate target after they held a 'war summit' in a south inner city pub at the weekend.
Dozens of members of the Hutch gang have been warned that their lives are in danger by gardai in recent weeks.
It is understood that a very close Crumlin-based associate of David Byrne put up a six-figure sum to avenge his death at the weekend.
He is not suspected of being one of the gunmen last night because he has been under major garda surveillance.
Two of the men involved in the shooting on Poplar Row are believed to have escaped in a car which was later found dumped in nearby St Patrick's Parade.
Crucially, it was not burned out, but it seems as if it was the intention to destroy it because a canister of petrol was found inside it.
Last night, Mr Hutch was described as being well-settled and respected in the Ballybough community. He had a number of convictions for small-time fraud and shoplifting.
Shortly after the shooting up to 120 people surrounded the home of Edward Hutch Snr last night.
Tensions were on a knife-edge as hundreds of people streamed onto the streets from the Ballybough flat complex.
Gardai struggled to come to terms with the event as a steady flow of people moved in and out of the small ground-floor flat before authorities could cordon off the area.
Less than an hour after the shooting gardai were investigating reports of shots being fired in Tallaght. However, there were no reports of any injuries in the incident. Sources said reports of shots been fired or a bomb going off were a trick often used by 'Fat' Freddie Thompson in the past to divert garda resouces to different areas.
Minister for Justice Frances Fitzgerald pledged to meet with senior gardai this morning to discuss the murder.
The shooting was "another deplorable example of the ruthlessness of gangland criminals", she said.
"It seems that some gangs are intent on waging a feud where human life counts for nothing.
"The gardai will take all necessary steps to try to prevent further bloodshed, but we have to recognise the challenges they face. Members of gangs who have fears for their safety should come forward to the gardai."
Local Social Democrats councillor Gary Gannon described the killing as a "needless tragedy".
"This level of depravity cannot be tolerated on our streets. But at this moment my thoughts are solely with the family of Edward," he said.
Meanwhile, Cllr Christy Burke hit out at the fact that armed checkpoints in the city failed to prevent the hit.
"This is what it has come to. You can be shot dead because of your name. If they can't get who they want they'll find a relative. It's shocking," he told the Herald.
"The gardai have lost it in my opinion. They don't have the resources they need and ordinary citizens need protecting.
"There were armed checkpoints around the city last night and all weekend, and still this happened. It was the element of surprise."
In the past Mr Hutch was suspected of helping launder some of the proceeds from the hiests carried out by his brother.
He was one of a large group of the Monk's associates targeted in Operation Alpha, the first major investigation launched by the Criminal Assets Bureau shortly after it was first established in 1996.
As part of the enquiry, which was to last over 10 years, the CAB seized a bank account in Eddie Hutch's name which contained over €156,000.
Prior to the latest murder garda sources revealed that fear was running high in the north inner city as people feared the Kinahan gang were "hell-bent" on revenge.
Just hours before the shooting senior gardai met in Ballymun where it was decided that there will be an increase in armed checkpoints across the city.
Not everyone involved in Friday's bloodbath has been identified.