Aaron Brady showed no emotion when the guilty verdict was read out to him in Court 19 of the Criminal Courts of Justice.
However, for the family of Detective Garda Adrian Donohoe, it was like a pressure valve being released, and after the strain of six-and-a-half years their tears flowed freely.
They have now turned their attention to seeing justice is served on the five other criminals involved in the Lordship credit union raid that night.
The family thanked everyone who had done the job of securing a conviction of capital murder, before vowing to bring the rest of the raiders before the courts.
Det Gda Donohoe's widow Caroline thanked the jury, her garda colleagues and the prosecution team on behalf of herself and her children Amy and Niall.
Then Det Gda Donohoe's brother Colm himself a det- ective garda, stood square in front of the nation's media flanked by his brother Martin and sister Mary.
He thanked the prosecution team, the judge, the staff of the DPP's office and the jury of 15 who were sworn in at the end of January.
"Their lives have been put on hold for the last six months, and the commitment they have shown through these challenging times has been humbling," he said.
"We would like to acknow- ledge each and every witness who gave evidence for the prosecution of this case.
"It is not an easy thing to come to court, and we do not underestimate the stress that this causes people.
"We would like to express immense gratitude to Adrian's colleagues in Dundalk who investigated this while trying to grieve for the loss of a coll- eague."
He pointed out that it had been one of the most comprehensive investigations in the history of the State, saying: "The professionalism and the quality of this investigation has been borne out by the fact that it has been able to withstand the most robust and forensic examination by the defence in this case.
"It is a huge credit to each and every person involved in the investigation that we stand here today."
The investigation into the robbery and the murder of Det Gda Donohoe was a transatlantic one because Brady had fled to the US after the killing.
Mr Donohoe acknowledged and thanked the "extraordinary help given to the investigation by law enforcement agencies around the world".
At this point in his statement on behalf of the family, he paused, steeled himself, and with a strong voice said: "Aaron Brady was not alone in Lordship on the 25th of January 2013.
"The quest for justice for Adrian will continue, and we appeal to anyone, near or far, who has any information and who may assist in this investigation, to come forward and do the right thing to bring those involved to justice.
"While justice has been done today, nothing will bring back Adrian to his wife, his two kids, his parents, his family, his coll- eagues and his friends.
"Adrian was a good man and the very least he deserves is that justice be served."
In the Garda depot in the Phoenix Park, senior management issued a direct statement to the raiders who were with Aaron Brady when they committed the robbery in which Det Gda Donohoe was murdered.
At a press briefing, Deputy Commissioner John Twomey issued the stern warning.
"There were other people involved in this horrific crime, and you will be brought to justice and we will make every effort and leave no stone unturned," he said. "I want to make an appeal to the people who committed the crime that we will be knocking on your door and we will make sure that you pay for this horrendous act.
"Our thoughts and our prayers are with the family of Adrian, with his wife Caroline and the extended family, and I want to take the opportunity here to thank the investigation team, the management standing behind me and the wider investigation team who are still working away, and I have a clear message that the investigation continues.
"We as a law enforcement agency will do everything we can to work with the community to bring the perpetrators to justice."
His views were echoed by Chief Superintendent Christy Mangan, from the Louth division, who said the conviction is a "step towards ensuring that all persons who were involved in the murder of Adrian, and the subsequent provision of assistance of those involved in it, will be brought to justice".
"We will never cease in our quest to bring accountability to those who have murdered Adrian. We owe that to Adrian's memory," he said.
Justice Minister Helen McEntee commended the gardaí for their "determined, persistent and painstaking investigation", noting also that there had been "crucial" cooperation from their colleagues in the PSNI and law enforcement partners in the United States.
The effort to apprehend those responsible had also been greatly supported by the local community in Co Louth.
"My hope is that this can bring some element of comfort to Detective Garda Adrian Donohoe's wife and family, his many friends and loyal colleagues," the minister said.
"The investigation will continue relentlessly so that others responsible for the dreadful events that night may also be brought to justice."