Nothing is going to stop s*** like this from happening. I am 100% for the second amendment BUT, quite literally the only way to stop people from shooting each other is to get rid of firearms altogether, which will never happen. I am not an anti weapon person by any stretch of the imagination, I enjoy shooting guns and such. It is a sad fact that this will happen again, just like Columbine, just like Virginia Tech, the movie theatre shooting, that mall in Portland last week, Newtown, and the dozens inbetween. The best we can do is keep our guard up, our eyes open and pray we make it through each day. Im sorry if that sounds harsh, especially to you parents and the parents of the children lost, but that is the truth.
edit: My heart does go out to those who lost loved ones before their time, I do not want to sound like a heartless prick. I can just see this exploding into a giant argument that will accomplish nothing.