I often wonder why he decided to tell me. Perhaps he had just made it up and was trying to impress me, or shock me, as I was in my teens at the time, having just arrived from Co Antrim to pursue my career in journalism. If, however, it was true — and I felt it was — could it be that having nursed the terrible secret for many years, he felt better getting it off his chest? Perhaps, but I don’t think he was having a twinge of conscience.

It has been my experience since then that people who commit wanton acts of violence seldom, if ever, express regret. During the Troubles I covered many cases in the Special Criminal Court in Dublin, including the trials of those accused of killing Senator Billy Fox, Lord Mountbatten, Detective Garda Seamus Quaid, Detective Garda John Morley, Garda Henry Byrne, and Sergeant Patrick Morrissey to name but a few. I remember some of the accused throwing a handful of coins at the judges to show their contempt for the non-jury court.

And even when they were found guilty they never expressed remorse for the terrible things they had done. Following the murder of Sgt Morrissey I watched gardaí chasing his killers through the cornfields of Co Louth. The sergeant, who was unarmed, had followed two men after they robbed the Labour Exchange in Ardee.

However, he was shot in the leg and when he was on his knees one of the raiders shot him in the eye at point-blank range. I described it at the time as an execution. How anyone could do such a thing was .