I think that, in general, linking movies and video games to crimes are overstated. I am sure that there are some examples where people lose touch with reality and emulate something that they have played or watched. I am sure there are also examples of people being so oversensitised by what they see in the media, news, games and movies that they lose touch with reality, but I think it is more of an exception then a norm.
Considering the violence of this crime, perhaps the accused was influenced by some form of media - whether it be the daily news, games, movies or songs (and yes the news, in my opinion, is the most influencial of them all). Why? Because it is real, and most humans can distinguish reality from fiction.
Speaking for myself, the music I listen to, the movies I watch and the games I play are chosen based upon the mood I am in at the time. For me, it is not the movie, music,games that dictate how I feel, but rather my feelings dictate what I am going to watch, listen to or play. It's a whole world of difference.
If people want to go on a crusade against violent video games and movies (I am not saying that you are Lera, just that it's quite common for the media to link whatever game or movie the kid was watching at the time to whatever crime they commit), then they should do so keeping in mind that the media, current events programs, and news that infiltrate our daily lives and highlight (somewhat) real events are the most pervasive of all media forms.
I am not saying that the media should be ostracised per se. But it is rare to find out the whole, unbiased, truth from them. If you want to find the truth in australia then you generally have to read abc news, then channel 9 or fox news - and the truth lies somewhere in between the two. Anyway, I am going on an unrelated rant here and I apologise.