But such evidence was hardly necessary. During his trial at the Old Bailey, dozens of victims' testimonies and depositions, along with a mass of forensic material, led to O'Doherty's swift conviction of 31 counts of attempted murder. These were the result of the notorious 1973 London letter-bomb campaign that O'Doherty had masterminded; two ounces of gelignite had even found their way through the post to 10 Downing Street. The IRA bomber received 30 life sentences, plus 20 years.
Now released from prison after serving nearly 15 years, and currently working on a PhD in English at Trinity College, Dublin, 38-year-old O'Doherty gives a graphic account of the making of an IRA man. Perhaps the book's greatest strength, and no doubt the very feature that, as O'Doherty predicts, will irritate, is the emotional tone in which the story is told.
He tells it how he saw and felt it at the time. When he is a stubborn, impetuous youth, he recounts as a stubborn, impetuous youth. When he is a blinkered perpetrator of callous violence, he recounts as a blinkered perpetrator of callous violence. When he becomes an older- but-wiser, committed pacifist, the tone shifts yet again to reflect that incarnation.
What the book does best is to convey the self-perpetuating nature of the terrorism. As he explains it, a particular brand of romanticism endemic to that part of the world feeds into viewing the fight as a just and noble one. Added to this, Protestants and Catholics have been weaned on so much bloodshed that revenge has become not merely sweet, but a 'moral' imperative.
He writes matter-of-factly about the inevitable beatings by warders and other miseries of prison existence, yet, ironically, it was there that he finally found the time and the inclination to reflect upon his life as a terrorist. He digested as many religious and philosophical books as he could get his hands on, admitting that 'everything I read I studied with a view to justifying the violence I had practised'.
But the more he read, the more he could not justify it. O'Doherty finally came face to face with his own naivety: 'I was not the shining idealist and justice-seeker I'd imagined I was. I was a serious human rights offender who had fallen for the mystique and aura of the tactic of violence and the old lie, Dulce et decorum est pro patria mori.'
He lays much of the blame for the continued violence on Catholic and Protestant church leaders: they lament the killings on the one hand, he notes, yet, on the other, they staunchly promote the existence of separate schools in Northern Ireland, thus perpetuating the deep social division.
At the end of The Volunteer, O'Doherty affirms that as singularly committed as he once was to making war, he is now as committed to promoting peace. The path for Northern Irish society lies, as he sees it, in all three sides - Catholic, Protestant and the British government - unreservedly admitting that they have 'blood on their hands going back generations' and that none should attempt to 'hijack the high moral ground and claim that it is too good to talk to the other'.
It is absurd, he maintains, to exclude paramilitaries from the peace talks; they, and only they, he argues, are capable of making a peace agreement worth laying down all arms for. After reading this compelling book, and recalling the newspaper headlines of recent weeks, it is hard not to concede that O'Doherty has a point.