The tribunal into the fatal shooting of Mr John Carthy at his home at Abbeylara in April 2000 heard yesterday that his killing was justified because he was "mentally ill" and posed a "lethal threat".
Mr Diarmuid McGuinness, for the Garda Commissioner and other senior gardaí, recalled earlier evidence presented to the tribunal as he and his colleague, Mr Cian Ferriter, continued their final submissions to the tribunal.
Mr Justice Barr, tribunal chairman, heard that Mr Carthy's mental condition had worsened in the months before the siege.
While he indicated no intention of wishing to take his own life, there was a lack of willingness to relinquish his shotgun from his person and his erratic behaviour at the time of the siege meant he was a "lethal threat".
Mr McGuinness told the tribunal that Mr Carthy had exhibited over the previous 24 hours his ability to use the gun and to use it in an unpredictable way.
He said Mr Carthy had discharged shots at or in the direction of where members of the Garda were or had been standing.
"Thirdly, he had emerged [from the house] with the weapon, albeit in a broken position, but failed to respond or heed the calls for him to put the gun down, and the hope that he was disarming the gun were dashed when he closed the gun again."
Testimony from police experts was also recalled to highlight Garda restraint during the siege. Quoting from an expert report produced for the tribunal, the testimony of former Det Chief Supt Michael Burdis recalled: "By US standards, Garda officers waited far too long before taking defensive action against Mr Carthy. As soon as Mr Carthy left the house there was an immediate threat to Garda personnel."
The tribunal also heard of Mr Carthy's behaviour in the days and months preceding the siege. Previous testimony from medical experts was recalled to the tribunal's attention which described how Mr Carthy at the time of the siege was "very ill and posed a serious threat to the gardaí".
Details of the post-mortem carried out by the former State Pathologist, Dr John Harbison, were also presented to Mr Justice Barr who heard that Mr Carthy was shot four times, with a total of nine entry and exit wounds found on his body.
The tribunal heard that the fourth shot which pierced his heart was the fatal shot. Evidence from the two Garda snipers who shot Mr Carthy was recalled as part of the submission, which detailed how they attempted to wound Mr Carthy first by shooting him in the leg.
Mr Ferriter, as part of his submission, asserted that the renewal of Mr Carthy's shotgun licence by gardaí was not questionable as, at the time, no complaints against him had been received.
Mr Carthy had also been successful in securing letters from his psychiatrist, Dr David Shanley, and his mother as to him being of stable mental condition to again handle a firearm.