Finally...
It's a tad hard of a concept for some people to understand, both "mature" and "immature" alike, I find.
Uuuhh.... FPS war games are okay, but not GTA? You still kill people. And you can even still be the bad guy in war games.
Yeah I guess that's the contradiction in my logic. Like Red Squirrel said, the older GTAs seem a bit more violent in some ways than GTA IV since you had access to chainsaws, katanas, hammers and whatnot. But one might argue that, that is just as violent (if not less) than calling in an airstrike or throwing a grenade to blow your enemies to pieces. I dunno I started playing games like Counter-Strike fairly young and I turned out alright. So he should be fine too.
Well, following that same logic, I played GTA at a young age. I started with GTA 2 when I was like 11-13, somewhere in there. Then I got GTA III the year it came out, I was 13? And at 11 I was listening to hardcore rap and vile music such as "ICP". I still turned out okay(arguably). Granted, I went through a "juggalo" phase, but it stayed just that, a phase. None of this "clown for life". But that's another argument for another discussion....
Point is, if you can handle killing people in videogames, you can handle killing people in videogames.