Garda sources have spoke of a major breakthrough in the investigation, through evidence obtained over the last two days.
Gardaí believe Monday’s morningtime shooting was carried out as reprisal for the murder of Eddie Ryan in the Moose bar in November 2000.
One suspect, in his 30s, has numerous convictions for violent crimes including arson, possession of fire arms and assaulting gardaí.
He was a close friend of Eddie Ryan and has close links to ‘Fat John’ McCarthy from Moyross who was jailed for 14 years at Limerick Circuit Court in 2012 for running what gardaí described as a ‘drugs factory’ at a derelict site near Moyross.
McCarthy, 44, was aligned to the McCarthy Dundon gang on the southside of the city and with the Eddie Ryan gang in Kileely, in a violent feud with the Keane Collopy gang in St Mary’s Park.
Kieran Keane, a brother of Christy Keane, and Phillip Collopy carried out the murder of Eddie Ryan after he tried to shoot Christy Keane two days previously.
That attempt failed when Eddie Ryan’s gun jammed.
Monday’s murder attempt on Mr Keane came as he arrived for a gym workout at the University of Limerick Arena. The man suspected of organising the attack was convicted in 2001 of an arson attack carried out on the home of a close relative of Mr Keane’s.
A number of people in the house had miraculously escaped the inferno.
The suspect for Monday’s shooting has been jailed in the past. Since his release, the suspect has been involved in serious crime.
In one incident, armed gardaí opened fire as he tried to ram his way through a checkpoint in a stolen car.
Meanwhile, Mr Keane, who was struck by four bullets in the attack, is reportedly out of danger at University Hospital Limerick. Gardaí were hoping to speak with him yesterday.
Mr Keane had been jailed in 2002 for 10 years after he being caught near his home in St Mary’s Park moving cannabis worth more than €220,000 in a coal bag.
Meanwhile, a man arrested on Monday night in connection with the shooting at UL, was still being held at Henry Street Garda station.