Contributes but only research can prove it.

I don't believe this can be established without extensive research but make the following observations:

1. As the games get more realistic, I believe they could desensitise the squeamish and even average person to violent acts.

2. To the undeveloped mind there could be a blurring between right and wrong as concerns violence i.e. the delusion it is has less impact than it actually has making it seem less than it is.

3. Much of the violent crime requires courage. Games aren't going to give you courage.

4. Much of violent crime is a result of brain chemistry. I doubt, very much, that games are going to effect brain chemistry. You're not going to turn into a psychopath playing a game.

5. I doubt that majority of people who are involved in violent crime have a lifestyle background of sitting on a PC playing games. They're far more likely to be outside hanging around in gangs.

I guess, to summarise, I can see games having an impact on a limited few who may want to reenact something they played but, even then, it seems that the step from watching a screen to doing it live would take more of a mental adjustment than just watching a game.