A 24-year-old man is being questioned in connection with the shooting of Martin Foley four months ago.
He was arrested in the south Dublin suburb of Ranelagh at around 8.45am and is being questioned in Crumlin Garda Station.
Mr Foley, 55, was shot several times by a man believed to be known to him as he drove his car out of a gym in Kimmage on 26 January. He later underwent surgery for his wounds.
It is believed the attack was linked to a feud between two Crumlin/Drimnagh based criminal gangs.
