Three people have been arrested in connection with the murder of Jeffrey Hannon in Limerick in November 2007.
Two men, aged 21 and 22, and a 21-year-old woman are being held at Henry Street and Roxboro Garda Stations.
Jeffrey Hannon's body was found by a local resident who was walking along in Galtee Drive in the O'Malley Park estate on the morning of 22 November 2007.
The 19-year-old had suffered severe head injuries.
To date 19 people have been arrested as part of the investigation into Mr Hannon's death.
