The man accused of the Bourke Street Mall car attack will be charged with multiple counts of murder as soon as police can interview him.
Five people, including a three-month-old baby and 10-year-old Thalia Hakin, were killed in the horrific incident at lunchtime on Friday.
Up to 13 other people remain in hospital amid grave fears the death toll could rise.
“They are critical. They’re in a very, very serious condition,” Victorian Premier Daniel Andrews told reporters on Sunday.
“The fear is of course that the death toll from this evil act will rise.”
Chief Commissioner Graham Ashton said the accused driver, Dimitrious “Jimmy” Gargasoulas, had surgery on Saturday afternoon after he was shot in the arm during the incident.
Victoria Police were still waiting for the go-ahead to interview him on Sunday.
Once charged, he would go before court as soon as possible, Mr Ashton said.
The 26-year-old was known to police and had been driving erratically around Melbourne after allegedly stabbing his brother that morning.
He had been on bail on other charges.
The situation has prompted Police Association secretary Ron Iddles to say the bail justice system must be scrapped and magistrates should oversee after-hour hearings.
“For too long we’ve done justice on the cheap whilst they’ve filled the void or the gap. We have modern technology now, we should have magistrates doing all remands,” Senior Sergeant Iddles told Fairfax.
Mr Andrews said bail laws would be reviewed following the attack.
“We are sad, we are angry, and we are resolute in making the changes that need to be made to learn from this and to honour that three-month-old baby and to honour all of those who have lost their live here,” he said.
“It’s just such a sad day. As a parent, it’s a very sad day. There can be nothing more innocent than a little three month old baby. That’s our focus today.
Prime Minister Malcolm Turnbull joined Mr Andrews at the memorial site on the steps of the old GPO in the mall.
“The loss of fellow Australians in such a shocking, wanton, criminal attack is a tragedy,” he said.
— ABC News (@abcnews) January 22, 2017
Mr Turnbull said all Australians were with the people of Melbourne. “We are with you, we mourn with you, we thank you, we love you,” he said.
Earlier, Opposition Leader Bill Shorten laid a wreath and praised the actions of his fellow Melburnians who helped victims straight after the incident.
“There is no satisfactory explanation, no set of circumstances which can condone this act of evil,” Mr Shorten said.
“What is the world coming to?”
— Cassie Zervos (@cassiezervos) January 20, 2017
A fund has been set up to help the victims of the attack, with the Victorian government putting in $100,000.
Mr Turnbull said the federal government would add to the fund, and he and his wife, Lucy, would make a personal contribution.
To make a donation, go to www.vic.gov.au/bourkestreet.
A vigil is being planned for Monday evening at Federation Square.
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– with AAP