A delusional narcissist urged the Queen to put an end to "out of control" corruption in Australia before shooting up Canberra Airport when "no one would listen" to him.
Ali Rachid Ammoun, 63, genuinely believed he was being persecuted and firing five bullets in the airport had a "bigger picture purpose", magistrate Ian Temby said on Friday.
Mr Temby made that finding in the ACT Magistrates Court as he sentenced Ammoun to three years and three months in jail.
He imposed a non-parole period of two years and two months on Ammoun, who had previously pleaded guilty to charges of discharging a firearm at a building and possessing a firearm without authorisation.
Ammoun, who served more than 14 years behind bars after attempting to murder his ex-wife in Western Australia, was on parole and living in Sydney at the time of the shooting.
His belief he had been "set up" by authorities in Western Australia led him to become a self-described "justice fighter", who spent three days planning an incident that will go down in history as the first time shots were fired in an Australian airport.
Mr Temby said Ammoun chose Canberra Airport because he "wanted the attention" and thought targeting a prominent place in the nation's capital would show the world he was innocent and his ex-wife had stabbed herself.
The magistrate said Ammoun, who suffers from delusional and narcissistic personality disorders, had reached the view he had "no choice" but to "make a big statement".
He noted the 63-year-old had exhausted his appeal rights in Western Australia and written to 25 people or entities, including Queen Elizabeth II, who had either not replied or declined to intervene in his case.
Ammoun therefore took a taxi from Sydney to Canberra on August 14, 2022, hiding a revolver in his bag and later loading it inside the airport terminal.
He fired five shots into glass windows within the building, then placed the gun on the ground while waiting for police to come and arrest him.
Mr Temby said more than 20 people were left with "feelings of fear and alarm", referring to 15 victim impact statements provided to the court earlier this month.
The statements revealed children, the elderly and people with disabilities were among the witnesses sent running and hiding in fear for their lives.
Some fled across the runway as confusion reigned, with a terrorist attack among the possibilities staff and passengers initially contemplated.
One woman, who was near Ammoun when he started shooting, described fearing she would get a bullet in the back as she scrambled to get away.
"Chaos" was a recurring theme of the accounts given by witnesses, some of whom have since been medicated to deal with the ongoing psychological stress.
Ammoun, who told a couple in the airport not to be upset because he would not harm them, recently gave evidence that he had no intention of hurting anyone.
He also claimed firing the revolver at the windows had not carried any risk because he could control "100 per cent" control the gun.
During lengthy sentencing remarks, which took Mr Temby nearly two-and-a-half hours to read, the magistrate said this comment demonstrated that Ammoun did not understand the dangerousness of his actions.
Mr Temby found Ammoun's disorders meant the offender had "a high degree of mental impairment", giving him very little capacity to understand the wrongfulness of his actions and the impact they would have on others.
However, he found Ammoun had known his actions were illegal and denounced the 63-year-old's claim that his behaviour had been justified.
Mr Temby said many people had, like Ammoun, felt dissatisfied with the outcome of legal proceedings.
It was "not an acceptable response", he said, to fire a gun inside an airport.
In sentencing, the magistrate said he had placed particularly great weight on the need to deter Ammoun and address the danger the 63-year-old posed to the community.
Ammoun, wearing a suit with sneakers, calmly whispered to defence lawyer Tamzin Lee and bowed to Mr Temby after learning his fate.
He has been behind bars at the Alexander Maconochie Centre, where he is employed as a cook's assistant, since his arrest on the day of the shooting.
With his sentence backdated accordingly, Ammoun will become eligible for parole in October 2024.
