The courage of those who faced a knife-wielding killer in a Sydney shopping centre has been praised by leaders as details emerge about him and his victims.

Joel Cauchi, 40, fatally stabbed six people and injured at least 12 more in a violent rampage at Westfield Bondi Junction on Saturday afternoon.

New South Wales Premier Chris Minns said many people ran “towards danger” including Inspector Amy Scott, who shot Cauchi dead at the scene.

“To the ordinary members of the public that cornered and confronted a murderer in the Westfield shopping centre, showing what I would call instinctive bravery under terrible circumstances,” he said.

“And of course, Inspector Amy Scott, who ran towards danger and showed professionalism and bravery and without a shadow of a doubt, saved many, many lives in the last 24 hours.

“We’re very, very grateful for the men and women that stood up in Bondi Junction.”

Tweet from @ChrisMinnsMP

Emergency services lauded

NSW Police Commissioner Karen Webb echoed Minns’ sentiment and commended the state’s first responders for their efforts.

“My thoughts go out to those people that were in the shopping centre, and as the premier has said, showed a great deal of courage yesterday.” she said.

“But also to the emergency services and of course, the police officers who responded to this very traumatic thing.”

NSW Police Assistant Commissioner Anthony Cooke said the man was known to authorities in his home state.

“We have received no evidence that we have recovered, no intelligence that we have gathered that would suggest that this was driven by any particular motivation, ideology or otherwise,” he told reporters on Sunday.

“We know that the offender in the matter suffered from mental health.”

Tweet from @SParnis

Queensland Police acting assistant commissioner Roger Lowe said Cauchi was living as an itinerant, relocating often across the state.

Cauchi had no known employment or partner and moved to NSW last month.

“We believe he has been sleeping in a vehicle or backpackers according to the family’s information,” Lowe said.

“Understanding that the family do not have regular contact with their son is periodic contact where he may respond to a text message.”

Lowe said Cauchi had not been arrested or criminally convicted over the past four to five years but was known to police.

Some victims identified

Six people, five women and one man, were killed in the attack and several others were injured.

Four female victims aged between 20 and 55 and a man, aged in his 30s, died at the scene.

A fifth female victim, 38-year-old osteopath Ashlee Good, died at St Vincent’s hospital on Saturday night.

Dr Good’s nine-month-old daughter was stabbed in the attack and is in a critical but stable condition at Sydney Children’s Hospital.

Also among those killed was Dawn Singleton, the 25-year-old daughter of multi-millionaire businessman John Singleton.

The male victim was working as a security guard at the shopping centre, NSW Police said.

Two of the six victims were from overseas and have no family in Australia, Cooke said.

At least 12 others, including nine women, two men and Dr Good’s daughter, were treated in hospital after suffering stab wounds in the attack.

Prime Minister Anthony Albanese said Scott, who was lunged at by Cauchi before he was shot, no doubt saved lives.

“The wonderful inspector who ran into danger by herself and removed the threat that was there to others, without thinking about the risks to herself,” he told reporters.

“We also see the footage of ordinary Australians putting themselves in harm’s way in order to help their fellow citizens.”

Albanese, along with Minns and local MP Allegra Spender, laid flowers at the scene on Sunday afternoon.

Opposition Leader Peter Dutton said there was heroism among the horror.

“We thank everyday Australians who helped each other get to safety and those who provided comfort to others in distress,” he said on social media.

Webb said Scott was doing well under the circumstances.

“She showed enormous courage and bravery.

“It was an awful situation … but it could have been much worse,” she said.

The shopping centre is closed and will be an active crime scene for days.

-AAP