Eamonn Barnes wears his 65 years lightly. Trim and fit, as befits someone who enjoys swimming in the open sea, and often breaking into an infectious laugh, he resembles nothing so much as a small boy on the last day of school before the summer holidays as he eagerly awaits the beginning of his retirement.
He has just returned from the conference of the International Association of Prosecutors, of which he is founding president, in Beijing. He is proud of the role of the Irish prosecution service in this body, and the influence it has had on standards around the world. Although it is only three years in existence, 86 countries were represented at its conference last week.
Mr Barnes is anxious to stress that he has no prescriptions for his successor in the job, Mr James Hamilton, who takes over today. He can only speak of what has happened in the past in the DPP's office, not on how things will be in the future, he says.
But he confesses to some surprise at newspaper reports on the newly announced Victims' Charter which said that files would be reviewed in his office if a victim or relative requested it, following a decision not to prosecute.
"That was always there," he says. "We have been reviewing decisions at the request of victims and aggrieved relatives for 20 years.
"The review is almost always done by an officer of higher rank, which is why some cases come to me. We have no inhibitions at all about reversing ourselves, though the proportion of decisions which are reversed would be low. They would tend to be where the original decision was based on a very fine judgment not to prosecute."
While he insists he cannot discuss individual cases, he recalls one instance where he personally reviewed a case as a result of a letter he received. The prosecution subsequently led to a conviction.
He is adamant that the Director of Public Prosecutions cannot give reasons for a decision not to prosecute.
"Our inability to give reasons is the single greatest inconvenience for this office.
"There are so many times when we're pawing the ground to give reasons, especially when people are making political capital out of it. If we could get around the issue of (a) injustice, and (b) defamation, we would be delighted to give reasons."
But giving reasons for non-prosecution would inevitably embroil the office in possible defamation and in injustice to the accused person, he says.
"So often the reasons have nothing to do with the guilt or innocence of the accused person, but with technical reasons, and if you go into that you convict the person."
He is very proud of having been Ireland's first DPP and of establishing the office. "We've established very high standards of justice in this office. We've never, ever prosecuted anyone for reasons of expediency. We've taken highly unpopular decisions, knowing in advance the storm clouds would break around our heads, and they did."
He says these standards sometimes meant that a garda would put a lot of work into a case and find it did not proceed, but relations with the Garda ana Siochana were still very good. He had nothing but praise for the Garda and its standards.
Were there not concerns about their standards in the 1970s, during the era of the "Heavy Gang"?
"The protection of suspects is something that the courts should take very seriously. There was a culture concerning this in the 1960s and 1970s following the Miranda decision in the US. [This related to rules governing the interrogation of suspects.]
"But the fact that the courts overturned certain decisions because the Garda did not observe certain rules does not mean that gardai were oppressive. I am satisfied that in recent decades they have gone to great lengths to ensure they have observed the law in their investigating techniques.
"We live in a very privileged society. When a lapse in high standards on the part of individual gardai occurs people are genuinely very shocked."
He is reluctant to criticise anyone on his last day in office, and is particularly anxious that his appreciation of the staff in his own office be noted. But he is conscious that his office has sometimes been the butt of criticism from members of the judiciary.
"Ninety-five per cent of them do their job, and do it very well, working hard and long hours. You usually don't hear from them. We have had occasion to be annoyed by a few exceptions."
His immediate focus is on a round of social engagements with his family, followed by a month in Cannes with his wife, when he will enjoy swimming in the Mediterranean. He may be contemplating a spot of lecturing and has already told The Irish Times he is looking forward to the opportunity to do some research.
The controversy which surrounded the job has sometimes been stressful, he says, and his children in particular were on occasion affected by it. "But they survived," he says cheerfully. So, clearly, has he.