Video-games influence HOW people kill people not why.
What?
I'm playing splintercell since they actually produced that game and yet I could never kill somebody like Sam Fisher does neither could I kill a person like in shooters (Counter Strike, Red Faction). You know what I mean.
The other thing is, I can't kill anyone at all. Why should I? I would ruin my life and I don't like to see real life dead people at all. I don't want to hold a gun and bla bla bla. I think you get the point.
I'm playing videogames with violence since I was eight and it didn't influence me at all. The only thing that it teach me is aiming better with the mouse and click faster with it.