Religion gets blamed for violence and blamed for evil events the god allows to happen. It's obvious that people who have turned their backs and closed their hearts to the love of God just don't understand faith and how free choice plays into that. A world without evil would have no personal challenge of faith. Maybe it is all BS but when believed it gives strength and helps people cope with things like this.
Many of you seem to think the govt can help by limiting guns but i doubt that would be the end of mass killings like this.