The head of Garda Síochána, Drew Harris, has met with the family of a man gunned down by the I.R.A. in 1983 to offer them an apology.
Chief Prison Officer at Portlaoise Prison in the Republic of Ireland, Brian Stack, was shot in the back of the neck after leaving an amateur boxing event in Dublin in 1983.
Mr. Stack succumbed to his injuries and passed away 18 months later in September 1984.
The I.R.A. initially denied involvement in the murder of Mr. Stack but admitted responsibility in 2013.
"Along with senior detectives, I met with the Stack family this morning to provide them with a briefing on the ongoing investigation into the murder of Mr Brian Stack," said Commissioner Harris after meeting the Stack family on Wednesday.
"I offered the Stack family an apology for the failings and shortcomings in the investigation. I fully acknowledge that these matters are serious and had a detrimental impact on the investigation.
"This investigation remains open and An Garda Síochána would appeal for anyone with information in relation to the murder of Mr Brian Stack to come forward," he added.