Do you think the media is responsible for school violence?

After school shootings, such as the Columbine shooting in Littleton, Colorado, people mostly seem to blame the media. The columbine shooters listened to Marilyn Manson and many people blamed the artist. I think the media has very little responsibility and that people blame artists like manson because he is easier to blame. Do you think that it is the media, and if not, what other factors do you think lead to violence among teens?