What a parasite. 50 years ago he’d be suing EC comics. If kids are stupid enough to be influenced by GTA, then it’s a wonder they didn’t become plumbers after playing Super Mario Bros, or spend all day trying to eat ghosts about a round of Pac-Man.
Heh I know, best not get too cozy here… 
As Gary Gygax - the creator of Dungeons and Dragons - once said, people have been killing each other for many millenia before even the written word was invented, so blaming violence on the media is stupid. Yeah, maybe these kids got the idea for a specific method of killing from a game, but the game didn’t make them want to kill.