I am going to venture a theory about how this murderous spree started. It's possible that only one of them had murder on his mind and a rifle in his hand. (An aside: if casings were found from a rifle, they can match those to the casings at the Prof Dyck scene). I doubt it's just an airsoft gun, as the two young campers seem to have been quickly killed, perhaps as they slept.
Anyway, one of them had the gun and murderous intent (this would seem to be BS). The other one may have thought they were just go to steal food and camping supplies. BS wants a permanent outlaw lifestyle, so he was looking to commit bigger crimes/kill helpless people. Once he killed that couple, he could tell his companion that they were both in this for good (his fantasy).
From BS's point of view, once those first murders occurred, it was going to be Him Against the World (and I'd expect the other teen was getting more and more agitated, tired and worried as time went on). IMO, people (especially inexperienced teens) with a grudge against the world actually think they can "accomplish" something by lashing out. They don't even realize how big the world is, or how their own physical needs (thirst, hunger, sleep, some comfort) are going to impact their choices. BS may have also had an extensive fantasy "playbook" in his head, whereby (to him) the Great North of Canada is the new frontier for survivalists and...sympathizers with his politics.
I think they are trying to go off grid, that they are ill-prepared, but that they can probably live on very little food and have some food with them. Will they get lost and eventually die out there in the wilderness? Will the one teen look for an opportunity to get away from murderous BS?
I would not call this psychosis on the part of BS, but more delusional (and perhaps paranoid) thinking. The delusions may not be fixed, so his behavior looks relatively normal (up until this). Neither of these teens has any sense of their own mortality, not really. They are in that "I don't give a F" about life phase. BS has committed murder in his head many times, once he did it for real, the excitement (scariness) of his new situation was (and maybe still is) an incredible upper, all that adrenalin, all these new "game-like" situations. They're operating as if this is a one person shooter game. They may try to ambush RCMP or others, I don't think they can stick to their "plan" of going off grid, at all. They will resurface.
MOO.
