As always there are more factors than just the game itself, I mean when you look at how many gamers are out there compared to these extreme attacks you see it's just that, an extreme.
Still let's talk about how many of those kids had access to 18+ games even though they are younger than 18, that is bad parenting. Maybe if the parents showed more responsibility the kid would have turned out to be a well rounded individual. Now I'm not saying a kid playing an 18 restricted game is gonna become a killer but think about it. 18 restrictions are there to cover the development gap when media glorifies sex, drugs and death.
