Andre Palmer, 26, was arrested Monday in his hometown of Brampton, north of Toronto, Staff Insp. Mike Earl told a news conference.
The arrest came the same day that police released security video from Sunday's robbery showing two men inside the bank — one brandishing a handgun and the other leaping over the counter before being tackled by a customer.
Palmer is accused of being "the vaulter," Earl said, adding police are still looking for a suspect who shot a teller while firing at the customer.
The 54-year-old man was shot in the abdomen when he followed the robbers out of the bank. Both remain in hospital following surgery.
"This individual fired a loaded handgun in a bank, injuring two people. We want to apprehend this guy as soon as possible," Earl said Tuesday.
Police say Palmer is charged with armed robbery, attempted murder, aggravated assault and two counts of possession of stolen property.
Earl said Palmer was known to police but would not elaborate. Nor would he specify what led investigators to Palmer, saying only that there was evidence at the scene and on the suspect that linked him to the robbery.
"There is property that was located on him that was stolen from the bank," he said.
The Canadian Bankers Association was offering a reward of up to $100,000 for information leading to the arrest and conviction of the suspects.
The actual amount paid was to be determined by the police, depending on the information received.
The suspects made off with an undisclosed amount of cash, although it's believed a bank security ink device may have stained most of the money, police said.