AN INQUEST into the Sydney siege has heard gunman Man Haron Monis killed Lindt Café manager Tori Johnson with an execution-style gunshot to the back of the head.
Mother-of-three Katrina Dawson died after a fragment of a police bullet ricocheted and hit a major blood vessel.
NSW State Coroner Michael Barnes this morning opened the coronial inquest into the events leading to three deaths, including Monis, during last month's siege in Sydney.
Counsel assisting the coroner, Jeremy Gormly, outlined the known facts and the evidence to be presented when the inquest reconvenes later this year.
"The hostages have had an experience that most of us would struggle to even imagine," he said.
"Difficult as it may be for them, it seems unavoidable that they will be called to give evidence.
"They are our eyes and ears and memory of what happened during those hours inside Lindt cafe."
Man Haron Monis entered the cafe with a pump-action shotgun hidden on his body, with both its butt-end and barrel sawn off.
He ordered and ate a piece of chocolate cake and drank some tea, then asked a waitress who had been serving him if he could move to a table closer to the rear doors.
"He would have been able to view the whole of the cafe," Mr Gormly said.
Half an hour later, Monis told the waitress he wished to speak to the manager, but did not give a reason why.
Tori Johnson sat beside him and the two started talking.
Staff who read their manager's body language could tell he was under some kind of stress.
"I need you to get my keys from the office and lock the door. Everything is okay. Tell the staff to be calm," Mr Johnson told a waitress.
Monis then put on a vest and a bandanna, stood at the table and said, "This is an attack. I have a bomb."
Everyone in the building was ordered to stand and move to the northern wall of the cafe.
Some hostages were then told to hold up a flag with Islamic text on it at the window.
"At present, it seems he had not made any contact with Islamic State before the siege," Mr Gormly said.
At 9.44am, at Monis's request, Mr Johnson placed a 000 and told police what Monis ordered him to - that Australia was under attack by Islamic State and a number of remote-operated bombs were hidden around the city.
The call lasted 12 minutes.
Police acknowledged the incident at 9.46am and were at the scene within five minutes.
The tactical response team arrived just after 10am.
Due to the nature of the phone call, the siege was treated as a possible terrorist attack.
Monis falsely claimed to hostages he had a bomb in his backpack, and did not remove the bag throughout the siege.
He fired a total of five shotgun cartridges during the stand-off - the first striking the area above the front entry door which opened onto Martin Place when some hostages escaped.
The second shot came at 2.14am.
It was the only bullet Monis fired which hit any person, despite his efforts to fire at police.
Mr Gormly said speculation Mr Johnson died while trying to wrench the weapon out of his captor's hands was incorrect, and that it was in fact an execution-style killing.
Tori Johnson was made to kneel on the floor and was simply shot "without further notice or warning" in the back of the head.
Ballistics and autopsy reports suggest the shotgun was about 75cm from the back of Mr Johnson's head when he was shot.
He died instantly.
A marksman witnessed the killing through a window and police stormed the building immediately.
They fired "flashbangs" into the building, also known as stun grenades, which temporarily disorient the senses by creating loud gunshot-like noises and blinding flashes.
Mr Gormly said there were 99 sounds and flashes which "can sound like a hail of bullets".
Monis fired two more shots at police - one at a window after hearing signs of entry, and another at the main door when officers entered - but failed to hit any of them.
"No shot fired by Mr Monis, other than the one that struck and killed Mr Johnson, struck anyone," Mr Gormly said.
After his death, Monis was found to have 21 remaining shotgun cartridges in his pockets and appeared to have been attempting to reload when he was killed, even though he still had two cartridges in the chamber.
An autopsy showed at least two bullets or bullet fragments hit Monis in the head, while another 11 hit him in the body.
Ricocheting bullet fragments also hit three surviving hostages.
Autopsies have been completed on each of the bodies, with Mr Johnson and Ms Dawson's remains returned to their families
"The remains of Mr Monis were buried, and no more needs to be said about that," Mr Gormly said.
THE coronial inquest will explore forensic analysis of every available detail relating to the siege, from the positioning of the police marksmen in surrounding buildings, to a ballistics assessment of Monis's sawn-off shotgun.
Mr Gormly said a 3D reconstruction of the scene had been generated at the exact moment police entered the building and segments of plaster walls struck by bullets had been removed for examination.
The police response will be closely scrutinised, with siege experts from the UK police to be flown in to provide an independent assessment.
Interstate police will also be called on to provide analysis in a domestic context.
"If there were defects in the management of the siege, they will be exposed," Mr Gormly said.
How police managed the hostages and their families during and after the siege will also come under the Coroner's gaze.
Mr Gormly said more than 300 000 calls were made during the 17-hour stand-off, all of which had to be investigated alongside thousands of social media posts and sound and video recorded within the cafe.
A psychiatric profile of Man Haron Monis has been commissioned in an effort to work out his motivation for the attack.
The inquest will investigate his associations and political activity, religious claims, record of public activity and media profile, litigation history, his personal and family relationships and his criminal history, including his wife's alleged murder.
"It's necessary to examine, without hindsight, how he came to be granted bail," Mr Gormly said.
"His gun history and the details of the gun he used in the siege are likely to be fairly well established in the evidence."
Neighbouring businesses have given police unfettered access to the relevant parts of their premises for investigation.
Mr Gormly said the inquest would look at the hard facts, and that engaging in "philosophical hypotheticals" served little use.
"All of us will have to try to imagine what it would be like... only armchair hostages have a confident answer to how they would have reacted," he said.
"What is needed from the inquiry is results that dispassionately, and without preconception or the benefit of hindsight, answer the questions.
"Some of the issues may be very difficult to confront, and I understand that Your Honour intends that families will be given a high priority in the consideration of how some materials will be managed.
"But all relevant issues have to be confronted."
The inquest will reconvene in a larger court at a later date, with both those details yet to be decided.
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