Specialist detectives are to launch a fresh investigation into the murder of Raonaid Murray.
The 17-year-old was stabbed to death nearly nine years ago near her home in Glenageary, South Dublin.
The Garda Serious Crime Review Team or 'cold case' unit is to begin a widespread investigation into the case.
The probe will be launched with a high-profile appeal by Gardaí and Raonaid Murray's family before the ninth anniversary of her murder on September 4.
Despite numerous appeals and thousands of statements, no-one has been charged with the murder.