Detectives probing the murder of a Limerick businessman were today tracing the movements of a car believed to have been used during the shooting.
Gardaí investigating the death of 35-year-old Roy Collins also made a fresh appeal for information about the killing in the Roxboro shopping centre on Thursday.
Two suspects, aged 19 and 22, who were arrested within an hour of the lunchtime killing at the Collins family's amusement arcade, remain in garda custody.
Gardai believe the shooting was a revenge attack because a member of Mr Collins' family had given evidence against a leading Limerick gangster.
Officers urged anyone with information about a black Mercedes-Benz - registration 06 D 528070 - to contact them.
A garda spokesman said the car was stolen in Dublin on March 30th.
"It was found at Mill Lane, Rossbrien, which is about a mile from the scene of the shooting," he said. "Members of the public may have seen this car along the route."
The Collins family had been under garda protection since the court hearing in 2005.
Mr Collins was working in the arcade, which is attached to the family-owned Steering Wheel pub, when he was shot.
His grieving father Steve maintains officers did all they could to ensure their safety over the past four years.
Labour's Limerick East TD Jan O'Sullivan said the recently announced ban on garda recruitment must not be allowed to hinder the battle against criminal gangs in Limerick and elsewhere.
"Gardaí must be given all the required resources to break up the gangs and bring the bosses to justice," said Ms O'Sullivan.
"The murder of Roy Collins last week was a despicable act and a crime against all civilised and democratic norms.
"A small minority has once again besmirched the name of Limerick but I know that the overwhelming majority of our citizens will continue to co-operate with the gardaí in fighting crime."
A 19-year-old youth was arrested at a house in the Ballinacurra Weston area of the city shorting after the killing. A 22-year-old man was arrested arrested around the same time in the Weston area of the city.
Both men appeared before a special sitting of Limerick District Court on Saturday where the State were successful in its application to have their periods of detention extended by a further 72 hours.
The application was made under Section 50 of the Criminal Justice Act 2007 which enables gardai to detain suspects for up to seven days.
Judge Aeneas McCarthy said he was satisfied that the murder investigation was being carried out in a "diligent and expeditious" manner and granted the 72 hour extension.
There was a large garda presence for the court hearing which heard that up to 100 gardai from across the southern region backed up by members of the National Bureau of Criminal investigation are involved in the murder inquiry.
Chief Supt John Kerin told the court that staff at the forensic Laboratory in Dublin would be working over the weekend on samples seized as part of the investigation.
The two men detained will have to be released from custody if they are not charged by lunchtime on Tuesday.