The fact that this stuff is even news is more than enough proof that videogames don't cause anyone to become violent. The connection is not videogames, but the fact that all of these people have been mentally unstable. If it wasn't the case, we'd be having mass murders every single day.
In other news, I've been playing The Legend of Zelda: Ocarina of Time Master Quest and Paper Mario. I've even played shooters in franchises such as Doom, Quake, 007, Half-Life, and Halo. I'm also very interested in trying out Serious Sam. Guess how that's affected me? Not in the slightest!