A man and a woman were still being questioned by gardaí yesterday following the shooting dead of a man in west Dublin on Saturday.
Meanwhile, another young man was in a critical condition in St James's Hospital in Dublin following a serious assault in the city centre on Saturday night.
The man killed in Blanchardstown was named as Dara McCormack (21) Whitestown Park, Blanchardstown. Two men were involved in the shooting at around 9pm on Saturday. Mr McCormack, who lived with his parents, was brought to Connolly hospital in Blanchardstown where he died at 10.45pm.
The male suspect was arrested at 5.30am on Sunday, and the woman at 3am. They were both taken to Blanchardstown Garda station. They were arrested under Section 30 of the Offences Against the State Act, which means they can be held for questioning for up to 72 hours without being charged.
Gardaí received intelligence about the attack, believed to be drugs-related, shortly after the shooting. They are also believed to be looking for another man in connection with the attack.
The city centre assault took place at about 10.30pm on Saturday, at the side of City Hall on Castle Street. Gardaí have appealed for witnesses. They particularly want to speak to pedestrians who helped the injured man, and people who travelled into town in a red Toyota taxi.
They also want to hear from a young couple who were travelling from the National Stadium on South Circular Road in a silver Avensis taxi, and who may have been heading for Doyle's bar. The number of the incident room in Pearse Street Garda station is 01-6669000.
The Blanchardstown killing was condemned by local Labour TD Joan Burton who said drug barons were acting with impunity. "I have repeatedly called for an increase in community policing in west Dublin. Areas affected by gun crime must have better police enforcement. We need also community policing to operate at street level and to work with young people."
She said the Minister for Justice had recently acknowledged in the Dáil that the number of dedicated community Garda officers in west Dublin had remained static over the past eight years.