Father of boxing world champion Katie Taylor, Pete, was among two people injured while a third was shot dead in an early-morning shooting at Bray Boxing Club on the outskirts of Dublin.
In a statement, a Garda spokesman said: "Gardai can confirm that one man aged 30 years has died following a shooting incident in Bray, Co".
Mr Ward said detectives were still working to establish a motive, saying gardai were not sure whether the attack was targeted or indiscriminate.
He said it was unclear whether the gunman had an accomplice.
The gunman then fled in a silver van with Northern Ireland number plates.
"We don't know if there was anyone else in that van with him".
Police believe the getaway vehicle drove towards Bray town centre and there have been several unconfirmed sightings.
The gym is owned by Bray municipal council and operated by Mr Taylor.
The Garda National Bureau of Criminal Investigation are assisting local units in the investigation, and members of the garda technical bureau commenced a forensic examination of the scene.
The scene is now closed off as gardai continue to investigate.
Ireland's Health Minister Simon Harris called the news from Bray "shocking".
"Another dark day for Bray".
Fellow councillor Michael O'Connor added: "Pete Taylor was shot".
The garda helicopter has been circulating the scene while the armed response unit is also in the area as gardai go door to door with their enquiries.