While access to information and justice is the main goal, former Taoiseach Bertie Ahern has said a State apology for the Dublin-Monaghan bombings “would certainly help”.
It has been 50 years since three bombs exploded in Dublin City and one in Monaghan, killing 34 people and injuring over 300.
No one was convicted for the bombings, but the loyalist Ulster Volunteer Force (UVF) admitted responsibility in 1993.
A memorial event is taking place later today on Talbot Street, Co Dublin, to remember the victims.
Mr Ahern told Newstalk Breakfast the focus of today should be on the family of the victims to allow them to grieve.
He added “every effort has been made” in the past 25 years to get as much information as possible about the circumstances surrounding the bombings.
“Nobody has ever been charged, that’s true, but [investigators] did bring it a long way,” he said.
He pointed out that Justice Henry Barron discovered the bombings were carried out by two groups of loyalist paramilitaries, likely with help from the Royal Ulster Constabulary.
It was revealed that shortly after the bombings, the UK Government told the Irish Government they suspected loyalist paramilitaries were involved.
The Irish Government, however, did not pass on this information to investigating Gardaí.
Mr Ahern recalled it was he who told this information to the husband of one of the victims in 1997, shortly after he became Taoiseach.
“I told him that and I looked at the files and the inquiry had ended – that wasn’t even known,” he said.
“It was extraordinary... it’s shameful to say for any even that killed so many people, that the inquiry effectively ended the August weekend of 1974.”
Dublin-Monaghan bombings
Mr Ahern said there were likely two reasons that the Irish Government at the time did not pass on its knowledge to Gardaí.
“The first is that there was an obsession with the IRA,” he said. “Because the following week, they started raiding safe houses all over Ireland.
“The second thing there was so many events happening at that time that the investigation teams were moving on all the time to other events.”
The Barron report ruled that the Fine Gael-Labour coalition at the time "showed little interest in the bombings" and did not do enough to help the investigation.
The memorial event will take place on Talbot Street after a Church service at St Mary’s Pro-Cathedral.
President Higgins will also attend a memorial event in Monaghan Town today to remember those killed and injured.
Minister for Social Protection Heather Humphreys will represent the Government in Monaghan Town.