Who to report a stalker to in Montreal?

Can you provide a specific location, like the intersection of two streets? It's possible that someone in the area might have captured relevant video footage from a surveillance camera that could be shared with authorities.

I purchased a dog/coyote spray in Cornwall, Ontario, at Canadian Tire. When I checked in Montreal, I couldn't find it. I had to provide identification and sign a document stating it was not intended for use on humans. The product cost $20 and I attached it to my keychain. So far, I haven't had to use it.