A Tallaght man suspected of active involvement in a 2017 Clondalkin feud murder was being questioned by detectives last night.
Gardai announced the arrest of the 22-year-old in the town early yesterday morning.
He is being detained at the local garda station in connection with the murder of John Gibson (28) at Fortunestown Lane at 9.20pm on September 18, 2017.
The Herald can reveal that the suspect was not previously known for involvement in organised crime and has no previous convictions.
"He is a suspect in this murder case but has never before run into trouble with the law apart from a minor drugs issue a number of years ago," a source said.
The murder of the father-of-two was the fourth of the entrenched Clondalkin drugs feud.
Gardai have been investigating if Gibson was targeted after swearing revenge for the murder of his pal Darragh Nugent (36).
Nugent was shot dead on Wheatfield Avenue, Neilstown, almost exactly a week before Mr Gibson was slain.
There have been no further fatal attacks since Gibson was shot dead in Tallaght, but the Clondalkin feud is still active according to gardai.
Both Gibson and Nugent were closely linked to jailed Clondalkin hitman James 'Nellie' Walsh who is serving a lengthy jail term for firearms offences. Gardai believe that their murders were carried out by a west Dublin crime group who were intent on "wiping out" Walsh's gang.
The gang suspected of murdering the duo are linked to the deadly Kinahan cartel and are considered west Dublin's biggest drug suppliers, but started conflicting with Walsh around seven years ago.
It ignited when Walsh's rivals murdered an innocent man, and in a revenge attack, their leader was shot dead five days later.
Jason 'Jay' Carroll (39) was shot once in the face and twice in the arm at his home at Cherrywood Drive, Clondalkin, on August 29, 2013.
It later emerged that gangsters close to Carroll had raised more than €100,000 to have Walsh shot dead.
At Gibson's funeral in Lucan in September 2017, his family called for an end to the "barbaric murders" in Dublin's gangland wars.