WARNING, DISTRESSING CONTENT: Seven News has obtained exclusive vision of the moment a 4WD ploughed through a crowd of Christmas shoppers in Melbourne's Flinders Street.
Investigators have spent the night examining the scene of Thursday's horrific attack, as witnesses say the car reached speeds of up to 100km/h.
Four people remain in critical condition, and a four-year-old boy with head injuries is among 19 people injured in the incident, including the 32-year-old driver who is an Australian citizen of Afghan descent.
The new footage shows the car pulling out onto the street as unsuspecting pedestrians make their way across the road.
Bystanders further down the road can be seen watching on in horror as the tragedy unfolds.
The white 4WD can be seen pulling onto the street. Source: 7 News
Just moments later, pedestrians were thrown into the air. Source: 7 News
The man, who was arrested by an off-duty officer, is known to police following a 2010 minor assault matter, and has a history of drug use and mental health issues.
"I, like, just like hear this big... Sounded like explosion, screaming. I sprinted down seconds after the crash and just bodies, just like everywhere," one witness told 7 News.
Other bystanders said the man was only slowed down by the pedestrians he hit.
Those hospitalised vary in age from four to 83, including an off-duty police officer.
Acting Police Chief Commissioner Shane Patton says the man was on a mental health plan but was not on bail or any corrections order.
Victoria Police has identified the driver as a 32-year-old Australian of Afghan descent. Source: 7 News
"He is still in custody, under arrest for these offences, for what we allege was a deliberate act," Mr Patton told reporters on Thursday night.
Mr Patton said there was no evidence to suggest any links to terrorism but investigations continue.
He said the man was alone in the car and accelerated as he drove on tram tracks down Flinders Street.
Police, who don't believe the attack was terror related, were on the scene within 15 seconds of the incident, Mr Patton said.
A second man, 24, was arrested after being seen filming the incident and was found with three knives in his bag although police believe he has no links to the incident.
Premier Daniel Andrews said the "evil and cowardly" act has affected all Victorians but urged the public to go about their festive activities.
The driver was dragged from the 4WD. Source: AAP
An ariel shot shows the aftermath the vehicle left in Melbourne's CBD. Source: Twitter/ Terminus Value
"At a time of the year when so many families are celebrating the end to the year, doing their Christmas shopping, making plans for what ought to be a festive season, we have seen a horrific act, an evil act, an act of cowardice, perpetrated against innocent bystanders," Mr Andrews said.
A day after the government announced a public memorial for the Bourke Street massacre, Mr Patton said authorities were working to prevent such attacks.
He said hundreds more police would be on the streets to give comfort to the public.
Prime Minister Malcolm Turnbull tweeted his thoughts.
"As our federal & state police & security agencies work together to secure the scene and investigate this shocking incident our thoughts & prayers are with the victims & the emergency & health workers who are treating them," he posted.