I think that this is true about it could happen anywhere, it seems the US media goes a long way to put this kind of stuff on television, it was a big deal in my country's media. I don't know how to use a gun, I havn't seen one up close, toy guns maybe. But people should be allowed to protect thier homes, however, where do you draw the line as to carrying it with you. Once it leaves your home it is not protecting the home. I think this is where things get complicated.
Being mentally ill is certainly a factor with this guy, so he must have thought he had a good reason to do all the killing. I guess we will never understand.