Javier Perry said he and others nearby felt sheer alarm as the car that ran down pedestrians just before 2.00pm on Thursday in Melbourne's busy Bourke Street Mall stopped just outside where he was ordering lunch.
"I was in Goldsbrough Lane, which is a food court exactly where the car came to a halt," the 36-year-old told SBS.
The suspect was arrested by police and is in custody assisting police with their enquiries, Victoria Police Chief Commissioner Graham Ashton told media on Friday afternoon.
Police have confirmed four people, at least one of those a child, had been killed in the incident.
Twenty others have been injured with, three in critical conditions and two in serious conditions.
"I was inside a small Japanese restaurant getting some takeaway when I heard a loud crash," Mr Perry said.
Initially he thought it was a car crash and was about to look, when he heard two gunshots followed by screams.
"A lot of panicked people ran into the restaurant, shouting to take cover."
He said they looked for somewhere to hide.
"Everyone ran towards the back kitchen area almost trampling over each other to get somewhere safe and lay low. There were two small girls crying inconsolably next to me."
After a few minutes, people from outside the store let them know the incident had been controlled, but it wasn't until he went back to work that he understood what had happened.
"I was very shaken up, but ok now," he said.
"Initially I was terrified and imagined the worst - that it was a gunman taking people out willy nilly, and whilst this wasn't a terrorist attack... it is in the back of the mind that it's almost just a matter of time unfortunately."
