The man in his 30s was shot dead at a youth centre in Blanchardstown at around 6pm yesterday evening.
It's believed he was shot up to eight times by a lone gunman who was dressed as a woman while a second man reportedly received gunshot wounds to his arm and is being treated at Connolly Hospital.
A man was arrested in Meath earlier this morning and is being detained at Blanchardstown Garda station.
