The police intervention comes after Toronto Transit Commission CEO Andy Byford asked Toronto Police Chief Bill Blair to have his force review the matter.
"I am concerned by the fact that there was a full on fight going on there. I am so concerned that I have called the police to review this independently," said Byford. "There needs to be a holistic review of exactly what happened. What happened from start to finish in order that the context is understood."
The incident took place Jan. 29 at Union Station, a major downtown transit hub, after a Toronto Maple Leafs hockey game.
A transit enforcement officer on duty was "assaulted" by two members of the public and consequently had to "defend" himself, Byford said. Another transit enforcement officer arrived to assist, and called for police intervention on his way to the scene, he added.
The matter did not involve a fare dispute, but what provoked the altercation remains unknown, Byford said.
A video capturing at least part of the incident was posted on YouTube and shows one transit officer holding a man against a wall and punching him repeatedly. Another officer is seen wrestling with an older man on the floor.
Police are eventually seen arriving and handcuffing the men. The two men were later charged with assaulting the transit enforcement officers and their cases remain before the courts, Byford said.
Both transit enforcement officers filed reports on the incident and an internal review of the matter raised no red flags, Byford said. No public complaints were made against the officers either, he added.
The two officers remain with the TTC but have been placed on administrative duties "purely as a precaution" while the investigation into the altercation is carried out, Byford said.
The police's Professional Standards Unit will lead the investigation.
Surveillance footage from the subway station where the incident took place will be among the materials it will analyse. Police will also interview witnesses and the transit enforcement officers at the centre of the matter.
"Trained staff are allowed to legitimately use force to defend themselves in certain circumstances. I'm asking for a professional independent review to say was that in fact justified," Byford said.
"At the end of the day, we don't want our members of staff to get into a fight, whatever the provocation, whatever the circumstances."
Transit enforcement officers received 54 days of training, Byford noted, with eight devoted to de-escalation techniques.
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