First off, you can't blame the parents. The father killed himself four years ago. The mother is in a mental hospital becasue she has brain damage from a car accident three years ago. That is why he killed his grandfather, becasue he was living with him instead. It is just a tragic turn of events coming to its final fruition. I guess if you could blame anybody it would be societies lack of compassion for one another. Or he could just have some crossed wires upstairs . . . we'll never know. As far as blaming Halo . . . that would be ludicruous. At Colombine they blamed Marylin Manson (despite the fact that boys wrote in their journals they hated MM, and actually musically foloowed Insane Clown Posse), the media also blamed Jethro Tull for that suicide along time ago. The reality is you could theroetically blame anyone you want. Why stop at music, why not blame Stephen King for writing "Rage"? Better yet lets starting banning books! (sarcasm) Where do you stop on that slippery slope? The reality is you can blame any media outlet you want (books, music, video games,etc.). The reality is that if the person is determined to commit an act of violence they will do it regardless of the influences about them.