Man Haron Monis carried out an act of terror when he held 18 people hostage in Sydney's Lindt Cafe, NSW Coroner Michael Barnes has found.
"The siege was a terrorist incident," the coroner said on Wednesday as he handed down his inquests into the fatal events of December 2014.
The conclusion on whether the 17-hour siege was a terror attack or not was important to assessing the actions of the agencies involved.
Experts on terrorism, radicalisation and Islamic State gave evidence at the inquest into the siege that resulted in the deaths of Monis, cafe manager Tori Johnson and Sydney barrister Katrina Dawson.
Monis had walked into the Lindt Cafe in Sydney's Martin Place on the morning of Monday December 15 with an ageing sawn-off shotgun and an Islamic flag and took 18 people hostage.
It ended when Monis was shot by specialist police who stormed the cafe after Mr Johnson was killed.
Ms Dawson was fatally wounded after being hit by police bullet fragments.
Mr Barnes looked at the command system operated during the police response.
"Generally, it worked well," he added.
The NSW Police Tactical Operations Unit was called out and a forward command post established.
"The transition from a system for dealing with a routine high-risk situation to that of a terrorist incident also proceeded swiftly and in accordance with relevant policies," Mr Barnes said.
"There is a clear dividing line between senior executive officers of the police force and operational incident commanders responsible for decisions about the management of a terrorist incident."
The primary police strategy was to contain and negotiate.
"That was adopted during the Lindt cafe siege. Sadly, it failed."
Mr Barnes' report examined how that strategy was applied.
"Contain and negotiate was the appropriate initial response to the siege. It continued to be so even after the siege was assessed to be a terrorist event" he said.
"How long it remained at the appropriate primary response depended upon a rigorous evaluation of its effectiveness. There was no evidence of an adequate examination was made."
He recommended the NSW Police Force review the training and accreditation of negotiators and consider drawing on international experience.
But Mr Barnes "readily accepted" the view of an international expert who told the inquest the siege "would have challenged any police force in the world".
For the NSW police force, "the challenge was greatly increased the fact that this was the first terrorism-related siege in Australia".
"Training and exercising cannot completely equip any organisation to respond to a novel threat."
