It is all but impossible to be proactive tracking down what Ralph Goodale referred to today as a lone wolf.
Seems like a lot of the Islamic terrorist attacks in North America are committed by "lone wolfs". They get associated to terrorist organizations because they are inspired and radicalized by their propaganda. Rarely do they make contact with these organizations or have planned to carry out their attacks with the organizations guidance.
This shooter in Quebec City was likely similarly radicalized and is a lone wolf only in the sense that he's not part of an organized group. There are a lot of losers posting racist and extremist views online, easily accessible on social media, even on this forum, and Trumpist terrorists are emboldened now more than ever.
They don't belong to cells that may be tracked by security agencies and the idea of expanding those same agencies surveillance capabilities I doubt would go down well with most Canadians.
Probably not. They'd have to monitor conservative hate groups, which make up a significant portion of the conservative movement. Conservatives freak out and cry about discrimination when the government monitors their terrorist activity.
The Quebec police could do something though. This is the ninth time the mosque has been attacked so it is obviously a known target to the police. An increased police presence in the area might help prevent any further criminal acts.
What Canada needs is it's own version of the US second amendment and Muslims need to arm themselves. I'm sure that will go over well.