We know that the shooter was a pro-NDP, pro Jack Layton internet troll as evidenced by his facebook page.  It seems there is only anecdotal evidence of the shooters anti-immigration positions, are delivered by left wing activists.  

We also know that Quebec saw the highest support for the citizenship ceremony niqab ban...was this shooting by this NDP supporter in response to the NDP adopting a pro-Niqab position that is contrary to his Quebec values?

Coupled with my post below showing Canadian citizens overwhelmingly support Leitch's enhanced immigration screening, was this attack a response to those NDP activists who did not agree with the majority of Canadians.

A mentally unstable NDP activist at odds with Quebecs anti-niqab, pro-immigrant screening values, likely created a breaking point in his warped mind.