The same point was made by Dr Richard Blennerhassett, consultant psychiatrist and clinical director of psychiatry at St Ita's, Portrane and Beaumont Hospital: "Qualities such as self-obsession, self-absorption, ruthlessness are the ones that are very much admired in our society and will get you to the top in journalism or business or medicine . . . Narcissism is valued in our society."
So the answer is no, she probably couldn't have been stopped, even on foot of a psychiatric assessment, says Dr Blennerhassett. "Had she been sitting across from me, I don't think there would have been anything much to find. I'd see a psychopathic personality make-up, the self-obsession, the need to have her own way, the kind of person who regards herself as one of those very special types of individuals who can only be understood by other very special types - as we saw when she wanted to put an ad in the local paper and would only deal with the editor.
"You could point to all kinds of aspects of her behaviour now and ask weren't there pointers to her make-up, but the reality is that up to the murder, there were some people who had nothing good to say about her, while others liked her reasonably well. And she would have been considered a fairly successful member of society, showing entrepreneurial skills, running around buying up property and running pubs."
But what about the pathological lying, the self-delusion, the notion that she was the empress of an empire, a character in a movie, that whole fantasy world she appeared to inhabit? All fit the picture of the sociopath. Or alternatively, in the view of Paul O'Mahoney, a picture of the purely selfish, someone who wants more and more and more, in the process devaluing other human beings to the point where a husband will be jettisoned as just another piece of excess baggage. And the point about Catherine Nevin is that just enough of her fantasies were coming true to make her think she was invincible.
"Her fantasies were based on the belief that she was wonderful and she had enough success to be confirmed in this," says O'Mahoney. "What she learned from life confirmed her in her self-love. Without much going for her, she ended up running a little empire, tyranically, but she was now a woman with power and resources, with a mini property empire and a social role in it - she only liked to deal with big-wigs, as we know. So she got away with that. And she had this feeling of invincibility; it had to come from within her own belief system, but it also had to have been re-inforced by getting away with it all her life. She had been approaching IRA men for years, making friends in high places, consorting with senior policemen and judges - so again, enough of the fantasies were coming true to confirm them in her own mind.
"Maybe at the beginning when she approached the IRA people, she was only trying it out, just to see what would happen, then let it lie. Then when there were no negative consequences, she was once again confirmed in the sense that `I can do no wrong, I can get away with it'. And meanwhile, the fantasies were building - `Wouldn't my life be wonderful if there were no holds on what I could achieve, on the money I had, on who I could marry . . ." And no hang-dog husband to look askance when she dallied with other men or threatened to spill the beans about their identities.
Who knows what path her life might have taken had she married a different man? Or, for that matter, who hasn't dwelt on Tom Nevin's horrendous luck in the marriage stakes? A first marriage annulled, a second that ended his life.
UNFORTUNATELY for Tom Nevin, Catherine Nevin was pretty good at using some pretence of love and sexual allure to get where she wanted. The profile of the stereotypical sociopath is of someone so deeply in love with herself that she is unable to love others. But she was obviously able to put on a good show when circumstances required.
Sociopath or not, she didn't have to go down that path to murder and self-destruction. So why did she? The classic backdrop for a personality disorder on this scale is a chaotic, abusive childhood where there is little love or care and few, if any, clear boundaries. But this doesn't fit with what we know of Catherine Nevin's upbringing. "There are some indications that such disorders may be linked to some minor brain abnormality relating to birth traumas or some such thing," says Dr Blennerhassett. "but it's not always the case . . ."
The irony is that far from suffering the low self-esteem of the emotionally deprived, Catherine Nevin had the unquenchable notion that she was wonderful: beautiful, sexually alluring, charming, astute and clever. "Makes you wonder about all this self-esteem talk," says Paul O'Mahoney.
In any event, so divorced from normal human emotions was Catherine the narcissist, that she failed to notice that by her own mouth and demeanour she had become her own nemesis. This is the woman who attracted suspicion with a flood of loose talk in the early stages, then compounded it by staring at her hands for 48 hours after her arrest.
Apart from her widely documented reading matter at the trial - Kipling, Heaney's Beowulf, Yeats, the airport blockbusters - she was also seen toting a textbook entitled Outline of Psychiatry. Perhaps by the time her life sentence is up, she might have it all worked out for herself.