Toronto's police chief is commending one of his officers for taking down a would-be bank robber while keeping the public out of harm's way.

After learning an east-end CIBC branch was being held up on Tuesday morning, Det. Const. Rob Armstrong walked into the bank dressed in plain clothes and slipped a note to the teller that read, "I am a cop, get me your supervisor."

At the time, the perpetrator was inside a manager's office, and had ordered tellers to bring him bundles of cash. The suspect said he had a gun and was threatening to hurt employees if he didn't get $150,000.

After Armstrong identified himself to the teller, an employee sounded the silent alarm and Emergency Task Force officers rushed to the scene.

Armstrong remained in the bank, posing as a client, and walked up behind the suspect after he left 50 minutes after he arrived.

When the would-be robber walked out the front door, Armstrong tackled him, which allowed officers to rush over and arrest the culprit.

On Wednesday, Chief Bill Blair watched the dramatic video camera footage of the takedown with CTV Toronto's Austin Delaney.

"He puts himself in harm's way, he puts himself between the danger and this innocent citizen and takes this guy down," Blair said. "I think it's clearly courageous action."

Armstrong didn't want to be interviewed. Blair said the officer is shy and wants to avoid the limelight.

The teller who received Armstrong's note, a woman identified as Nella by her husband in an interview on Tuesday, was one of three employees forced to bring cash to the suspect

Meanwhile, a 16-year-old boy charged in connection with the holdup was out on bail at the time of the incident. He made a court appearance on Wednesday.

With a report from CTV Toronto's Austin Delaney