The Barr Tribunal has heard that John Carthy behaved in a 'reckless' and 'self-destructive' fashion over the course of the Abbeylara siege.
Professor Thomas Fahy, who is a specialist in the field of forensic mental health at King's College, London, told the inquiry that Mr Carthy's actions suggested he paid 'scant attention to his own safety'.
Prof. Fahy said the possibility that he wished to end his own life could not be ruled out.
Mr Carthy was shot dead by members of the Garda Emergency Response Unit at the end of the Abbeylara siege in April 2000.
He had suffered from bipolar affective disorder for a number of years.
In his second day of evidence, Prof. Fahy told the tribunal he believed Mr Carthy was motivated by a self-destructive nature, born of his mental illness, over the course of the 25-hour siege.
However, he admitted that because of his psychotic state at the time, Mr Carthy's 'reckless' behaviour may have been sub-conscious.
