Waterloo Regional Police confirm a conductive energy weapon was used during an arrest on Mill Street on Tuesday night.
Police are releasing few details about the incident at this point, only saying that a crime was committed elsewhere and the investigation led them to a suspect on Mill Street.
A neighbor, who did not want to be identified, says she heard a commotion on her street, and could hear the sound of a man being tased.
“I heard some yelling and when I looked out the window, I saw the cop tase the guy,” the neighbour said.
Police say a man was taken to hospital after the altercation.
Mill Street remained closed for a number of hours after the incident.
The SIU has invoked its mandate to take over the investigation, which typically happens when a civilian has been injured during an arrest.
With reporting by Max Wark.