The politics of division almost always result in bloodshed. It is only when all sides mutually agree to divorce that things may go peacefully. The Czechoslovakia is an example.
We live in a world of identities. Nation-states, races, gender, classes, ethnic, religious, cultural identities inform to greater or lesser extent how people see themselves as individuals and individuals in society. We as a species have not quite managed to privilege ourselves as species first.
We do not yet fully share a common sense of humanity and remain only partly emerged from our tribal caves.
As reprehensible and inexcusable as the shooting and murder are, they will not be the first if the PQ pushes for sovereignty. There are too many identities bound up in the equation for it go peacefully. Francophone, Anglophone. Canadian, Quebecois, Aboriginal. Sovereigntist, federalist.
Any party openly calling for secession in opposition to the national will is playing with lives. Any national government enacting policies that spawn secessionist rhetoric and acts is playing with lives.
I can't support any of them.