Five violent killings in six days in the Irish Republic have piled pressure on the Irish government to take action.
An innocent plumber was shot dead in a double killing in Dublin
In the latest incident, Gerard Byrne, 25, was shot dead near the city's financial district at about 2100 GMT on Wednesday. He was well-known to police.
Tanaiste Michael McDowell said that a lack of policing resources was not to blame and "all the arms of democracy" were needed to combat violent crime.
Opposition parties want Mr McDowell, who is minister for justice, to resign.
Politicians are calling for a similar response to that which followed the wave of revulsion over the 1996 murder of journalist Veronica Guerin.
Jim O'Keeffe of the opposition Fine Gael party said that law and order had broken down and Ireland was in a virtual state of national emergency.
The upsurge in violent deaths has seen four other people killed in the last six days.
Last Friday, postmaster Alan Cunniffe was shot dead in Kilkenny, while on Tuesday evening, Dundalk man Aidan Myers was killed outside the town as an armed gang went on a cross-border crime rampage.
Earlier on the same day, Martin 'Marlo' Hyland, 39, believed to be a major drug dealer, was shot dead, along with Anthony Campbell, an apprentice plumber.
Journalist Veronica Guerin was murdered in Dublin in 1996
The innocent 20-year old happened to be working in the house in Finglas, County Dublin, where Hyland was staying, and is believed to have been shot once after answering the door to the killers.
In parliament on Wednesday, Taoiseach Bertie Ahern was forced to defend efforts being made to combat organised crime.
Mr Ahern said that the success of the gardai's Operation Oak - which aimed to stop Hyland's criminal activities - was the reason he was killed by gunmen who were believed to be former associates.
"There is no doubt that as a result of garda operations, the net was tightening around Martin Hyland and he was losing grip of his criminal activities," he said.
"Many of his associates have been arrested - 43 of them - and 24 have already been charged with serious offences.
"The gardai gave me the figures from Oak. They have seized 30kg of heroin, 35kg of cocaine, 1,500kg of cannabis, stolen vehicles, handguns, AK47s, sawn-off shotguns, rifles, ammunition, cash.''
Hyland, who was one of the country's biggest drug dealers, was hit six times in the head and body as he slept in an upstairs bedroom in a relative's house.
Although Hyland was allegedly linked to the IRA, Mr Ahern told the Dail: "I've seen nothing that may suggest that the Provisional IRA was involved."
And rumours that the double murder was carried out by convicted INLA killer Dessie O'Hare, known as the Border Fox, were denied by his spokesman.
Convicted INLA killer Dessie O'Hare denied involvement
"From a garda point of view, it will be too early to say exactly who done it, but Dessie O'Hare is absolutely not in any way connected to any type of gangland killings," he said on RTE radio.
"He's been working with the Brothers of Charity in the west of Ireland, he's working with the handicapped, he's been to Lourdes.''
Mr McGarrigle said that under the terms of O'Hare's extended temporary release from prison, where he served a lengthy sentence for kidnapping a Dublin dentist and cutting off parts of his captive's fingers, he will be returned immediately to prison if seen in the company of subversives.
In the latest killing, Gerard Byrne, was shot up to five times in the head outside a shop in the IFSC area, not far from Connolly Station.
The shooting happened at about 2100 GMT on Wednesday.
He had been implicated in a hand grenade attack on a property in north Dublin.
He was arrested a few months ago in Raheny on Dublin's northside when, Gardai believe, he was on his way to commit a murder.
Gardai also believe the killing may be linked to a long-running feud between two north-inner city Dublin families.
Gerard Byrne is known to have taken the side of a woman whom, it is claimed, was raped by a leading underworld figure.