A man has been arrested by gardaí investigating the murder of Alan Ryan in Dublin earlier this week.
Mr Ryan (31), a member of the so-called Real IRA, and another man were shot in a gangland style attack at Grange Lodge Avenue, Clongriffin, on Monday afternoon.
The second man is expected to make a full recovery.
Gardaí arrested a man in his 40s in connection with the incident last night.
He is being held at a Garda station in the north city under Section 30 Offences Against the State 1939, a Garda spokesman said.
It is understood Ryan was visiting family members close to his own home and that he was ambushed on the street when leaving.
Gardaí believe a car carrying two gunmen pulled up and at least one of the passengers got out and started firing at Mr Ryan and the other man.
Mr Ryan was hit a number of times, including as he lay wounded on the ground. He was shot at least once in the head by the masked gunman, who then ran back to the waiting vehicle and was driven off at speed.
Gardaí found a burnt-out car at Hole in the Wall Road in Donaghmede which the investigating team of detectives believe was used by the killers.
The investigation is ongoing.