The columnist is clear, but he ignores the fact that due to past systems' failures, the governments of the day closed many of the long term institutions (in Vancouver, Riverview) that people with ongoing mental medical conditions were housed and taken care of.    

Instead they were released to the community, the support networks either failed or were not adequately present - and ultimately many of them ended up on the street.

Training police may help avoid a tragic outcome from an incident - but it won't stop the incident(s) from happening.