A third man has been arrested by gardaí investigating the murder of Vincent Ryan in Dublin last month.
The 43-year-old was arrested yesterday evening and is being detained at Blanchardstown Garda Station.
Mr Ryan died after he was shot several times while sitting in his car on McKee Road in Finglas on Monday 29 February.
The 25-year-old was well known to gardaí for his involvement in dissident republican activity.
One man was yesterday released without charge in the investigation, while another man remains in garda custody in Finglas.
Gardaí have again appealed for anyone with information to contact Finglas Garda Station on 01-6667500, the Garda Confidential Line on 1800-666-111 or any garda station.
