The Garda Commissioner Martin Callinan has said gardaí will continue to carry out a "robust and committed" investigation to find those behind the murder of Detective Garda Adrian Donohoe.
The 41-year-old was shot dead outside the Lordship Credit Union in Co Louth on January 25 last year.
Family and friends of the late Detective Garda turned out to attend a special memorial service in Dundalk in county Louth yesterday evening to mark the first anniversary of his murder.
Mr Callinan said Gardaí know the identities of those who carried out the attack, but he is appealing to anyone with information to come forward.
Commissioner Callinan also paid tribute to the people of Dundalk for their support over the past twelve months.