Joel Cauchi spent the day of April 13 walking around a Sydney shopping precinct and eating at a Bondi Junction restaurant before the bloody rampage began.

Cauchi's family, like many other Australians, are "still trying to comprehend what has happened".

His family said in a statement "he has battled with mental health issues since he was a teenager".

"We are in contact with both the NSW Police Force and Queensland Police Service and have no issues with the police officer who shot our son as she was only doing her job to protect others and we hope she is coping alright."

CCTV footage of Cauchi entering multiple stores has surfaced after the April 13 tragedy.

He is first seen entering Saigon Noodle, a Vietnamese restaurant in Bondi Junction's Oxford Street Mall, just after 10am.

Staff said he ordered a curry but was unable to pay and left shortly afterwards.

At 12.22pm CCTV footage at Saigon Noodle shows the 40-year-old re-enter the store before ordering the same meal, paying and sitting down to eat.

Half an hour later Cauchi is seen leaving a Daiso store on Oxford Street.

Around two hours pass without an indication of where Cauchi is. At 3.10pm he is seen on Westfield CCTV entering the shopping centre and leaving again.

The same footage shows Cauchi returning to Westfield ten minutes later and lunging at shoppers. This is when his stabbing rampage began.

Cauchi stabbed 18 people during this time, causing fatal injuries for some.

Dawn Singleton, Ashlee Good, Yixuan Cheng, Faraz Tahir, Jade Young and Pikria Darchia have been identified as the murder victims.

A number of civilians were heralded as heroes including two French men, Damien Guerot and Silas Despreaux, who held the attacker off with bollards and chairs during this time.

NSW Police inspector Amy Scott was the first responder on the scene and CCTV showed her running after the attacker with a group of brave civilians.

Shortly after Inspector Scott found Cauchi he turned towards her holding the knife and was shot dead.

Westfield remains locked down as the crime scene is forensically examined.

A memorial has been established outside the shopping centre where heartbroken community members, including Anthony Albanese, Chris Minns and Malcolm Turnbull, have laid flowers.