Here we go again! Some crazy wants to go out in a blaze of glory killing people he doesn't even know. It's been going on a long time and will go on for a long time. We will debate around and around as to whether we need more or less gun control.
If you're over fifty, you may remember Charles Whitman, the Texas Tower shooter, who killed 16 and wounded 32 on August 1, 1966. See http://en.wikipedia.org/wiki/Charles_Whitman.
And on and on it went. Last year it was in Norway which supposedly has strict gun control. Last week it was at a movie theater in Colorado. We'll probably see some copycat attempt in the next month or so. Our only solutions will be to point fingers at those who oppose any gun control and at those who "want to take guns away from freedom lovers". For a really well-thought out discussion, see http://www.salon.com/2012/07/22/jason_alexanders_amazing_gun_rant/.