I have come across a couple (my topic will be cognitive remediation and computer games, so i've come across a few computer game and violence related articles in my search by accident). Haven't saved any - but if you go to the 'PSYCHINFO' database and put it in the search engine you will find some.
From what i remember, they didn't generally do a good job in showing a direct link. Most aren't experimental, they use pre-existing populations - so they are along the lines of ' kids that play violent games are more likely to be violent.' That could, however, mean that violent children tend to play violent computer games and not the other way around.