He had a blog where he described his ideal as dying like Romeo and Juliet or under a hail of bullets. He also said that he hated "jocks", and that he felt life was like a video game (except that he forgot: real life does not have reset button, cheat code and multiple lives). He was very gothic, and enjoyed violent videogames.
I guess he just reached his limit and simply broke in a fury of hatred. So, no real specific motive, he just enjoyed the concept of killing.
What we can wonder is, why isn't there some sort of monitoring of blogs by people who are real wakos, and say so themsleves so that psychological help could be provided?
Oh, and for the record: police did not kill him. He was taking two people hostage and a policeman shot him in the leg. He fell to the ground, got his handgun out and shot himself in the face. Perhaps he should have started by doing that.
Source(s):
Montreal newspaper La Presse