SALT LAKE CITY (AP Modified, ABC4 News) — The Salt Lake City’s Civilian Review Board sustained an allegation that a police officer used improper force during a protest against police violence in May when he pushed down an older man with a cane.

Video captured by ABC4 shows an officer getting out of an armored police vehicle and hitting a man as he was walking away from the officer, the man fell to the ground.

The county district attorney’s office is reviewing whether or not to file criminal charges against the officer. The Salt Lake City Police Department is still conducting an internal investigation. It is unclear how long the internal review will take.

Police Chief Mike Brown had previously called the officer’s conduct “inappropriate.” Salt Lake City Mayor Erin Mendenhall said, “it seems to be well outside the protocol.”

The Tribune confirmed that the altercation prompted recommendations from the civilian review board on how the department should respond to big protests in the future.

According to the Associated Press, the board suggested the department should review its policies, particularly the use of armored mine-resistance militarized vehicles, arguing officers are not trained in using the vehicles and the presence of them at protests amplifies public stress.

Police spokesman Keith Horrocks said he couldn’t say whether the department would enact any of the board’s recommendations, and he couldn’t answer why the militarized vehicles were deployed that day, because the department hadn’t finished its own internal review.

Horrocks said Brown would take the panel’s suggestions into consideration when making a decision.