i think its just the excuses used by offenders' and their parents thoughts that the games change how people are. At the end of the day your either susceptible to violence in games changing you or your not, likelihood the persons already a violent person anyway and playing the games just meets what they like doing and gives them their 'kicks'
i play all sorts of what can be deemed 'violent' games, but in the real world im unchanged, if someone tries picking a fight with me i wont react, im the sort of person who will calm situations down.
I dont think it should be down to one persons opinion and decision to stop 'everyone' from doing something that they dont approve of, when it (in my case) doesnt change my real world personality or temporoment.
Afterall, its easy to say, im a really nice person, i saw 'such and such' in a game and wanted to do it, please dont prosecute me officer. I think thats where all the psychologists or whatever gather their opinion from, its just easy to say oh they play violent games therefore theyre going to be a violent person.
If I play football games does that therefore make me a world class international player? hehe nope