There's a lot of issues that need to be addressed, and like you said Donutz, we don't need to do it with a knee-jerk reaction based thinking.
There are so many questions I have regarding this issue...
What possesses gun owners to have guns out in the open, free for anyone to grab and use? Not to mention, wide open when the members of your home have documented mental issues?
Where was the local school police officer? I'm not saying he/she could have stopped the attack, but for a school with a brand new security system installed I would think they would have had a local officer at the school. When I was in high school we always had an officer at the school. I don't have kids of my own yet, but those who do say there's trained, full time officers at the school during all operational hours?
Furthermore, my place of work has a more stringent policy for allowing visitors on site. Why are school so easy to access and get into? Hell, I have to badge in through three or four doors to even get out to the offices and out to the shop floor? Why would schools not have a reception area that requires badge access or other type security before parents or random strangers can get into the class rooms? Makes no sense to me.