Why is hip hop being blamed for school shootings?

Drake asked:


As with this cleveland school shooting case people once again start blaming hip hop music. I am not condoning much of the violence and misogamy that hip hop music has, but just like the Colombine shooters this kid from cleveland was not into the Hip hop culuture he was a white kid that was more into the Marylin manson and general goth scene.
This is John Gibson making that accusation
http://mediamatters.org/items/200710110004?f=h_latest