The incident happened at a post office at Woodbine Park, Blackrock on January 19th
A man in his 40s is due in court in connection with an armed robbery in Dublin in January.
An armed man wearing a mask entered the post office at Woodbine Park, Blackrock at around 2.30pm on Tuesday 19th January.
He threatened customers and staff and fired a number of shots before leaving the scene on foot. Nobody in the post office was injured.
While fleeing the scene, the man was challenged by a male passer-by. The passer-by sustained minor injuries during the altercation.
Gardai in Donnybrook arrested a man on Monday in connection with the incident.
He is due in court this afternoon.