Gunfire explodes around Sydney Siege survivor as police storm Lindt Cafe

Newly released CCTV shows gunfire seen exploding in all directions around Sydney siege survivor Louisa Hope as armed authorities storm the Lindt Cafe.

She is the last of the hostages to give evidence at the inquest into the December 2014 siege and has revealed the terrifying final moments of Man Monis killing cafe manager Tori Johnson, prompting police to storm the cafe.

Siege gunman Man Haron Monis was psyching himself up like an "athlete preparing for a big event" before he shot Lindt Cafe manager Tori Johnson, an inquest has heard.

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Ms Hope was sitting with her eyes closed and in prayer when six other hostages fled the cafe shortly after 2am, she told the inquest on Thursday.

"I opened my eyes and realised everyone was gone," she said.

Ms Hope, her mother Robin Hope, Mr Johnson and fellow hostages, Katrina Dawson and Marcia Mikhael still remained.

"I made the assumption he would probably come out and find me and kill me," she said.

Instead Monis had ordered Ms Hope and her mother to stand either side of him, before calling out to Mr Johnson and telling him to kneel down with his hands on his head.

He then began "psyching himself up" as he scanned the room from side to side, apparently worried police were about to enter the building.

He was "huffing and puffing ... like an athlete preparing for a big event", Ms Hope said.

"Then he shot the gun and I felt the gunshot ... Tori fell forward with his hands still at his head."

On Wednesday hostage Selina Win Pe said that moments before Mr Johnson was killed, she heard a male Australian say the words, "'Oh my God',".

Ms Hope said she was confident that was not the case, while also praising Mr Johnson.

"Tori Johnson stayed with my mother and I'm grateful," she said.

The siege came to its deadly conclusion at about 2.14am when police stormed the building upon hearing the shot that killed Mr Johnson, having employed a "contain and negotiate" policy until that point.

But the inquest also heard on Thursday that police and security agencies should have picked up on signs Monis was becoming more radicalised.

A month before Monis seized control of the cafe in Sydney's Martin Place, he publicly pledged allegiance to Islamic State. He had also previously written to Attorney-General George Brandis about contacting the extremist group and had been charged in relation to a murder.

Dr Kate Barrelle, a clinical psychologist with expertise in radicalisation, said Monis was "undoubtedly a terrorist" but he was "atypical".

Counsel for Ms Dawson's family, Phillip Boulten SC, put it to Dr Barrelle that there were signs over a long period of time that Monis had become fixated on ideological and political beliefs and had demonstrated no signs of deradicalisation.

"I suggest police and security agencies, people charged with keeping us safe, should have picked up on the fact that he was charged with murder and continued to carry on in this ideological fashion as fair predictors of him being inclined to commit a terrorist attack," Mr Boulton said.

Dr Barrelle replied: "I say that I think that's a very reasonably formulation."

The inquest continues.

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