Detectives were today granted extra time to quiz two men about the murder of Limerick business man Roy Collins.
The suspects, aged 19 and 22, were arrested within an hour of the lunchtime killing of the 35-year-old father of two in the family's amusement arcade in the city's Roxoboro shopping centre on Thursday.
Gardai believe the shooting was a revenge attack because a member of Mr Collin's family gave evidence against a leading Limerick gangster.
The family had been under Garda protection since that court hearing in 2005.
The Assistant Garda Commissioner Kevin Ludlow reassured the people of Limerick that gardaí will put an end to the ruthless criminal activity in the city".
At a press briefing in the city this morning Asst Commissioner Ludlow said Gardai had been "heartened' by the support they had recevied from the people in their investigation to date.
Mr Collin's grieving father Steve has insisted that officers did all they could to ensure their safety over the past four years. He also said his family would not be forced to leave the city because of his son's killing.
A court today granted gardai another 48 hours to question the men.
Roy Collins was working in the arcade, which is attached to the family owned Steering Wheel pub, when he was shot once in the chest shortly after midday on Thursday.
He was rushed to the Mid-Western Regional Hospital but died a short time later.
Garda Commissioner Fachtna Murphy yesterday vowed today that no resource would be spared in bringing to justice the killers.
A post-mortem examination showed that Mr Collins died from trauma to the body as a result of a single gunshot wound.
Mr Murphy said he was making specialist Garda units available to crack down on feuding Limerick gangsters.
"Experience has shown us that, by co-ordinating resources, targeting our activities and working with the community, we have successfully disrupted much criminal activity and placed many of those involved behind bars," he said.
"I am conscious of the difficulties facing potential witnesses in these cases but I am determined to ensure that intimidation will not be allowed to disrupt the criminal justice process".
Mr Murphy said Limerick gardai had his full support in confronting and facing down criminals who were destroying the good name of the city.
"They will not succeed and An Garda Siochana will do its utmost, in accordance with the rule of law, to bring those responsible before the courts," he said