Vancouver should invest in an Active Denial System. Millimeter wave "death ray" that makes it feel like your skin is set on fire. Once out of the beam, the effect ends. It's a preferable to things like rubber claymore mines, tear gas, or the Long Range Acoustic Device (LRAD), most of which have the potential to cause more permanent damage.
As we've seen in many countries during the Arab Spring, lethal force against protesters should only be an option if the officier/soldier is being equivalently threatened.
Disclaimer: I do not work for Raytheon.