Leaving the general 'ick' of much of this thread behind for a moment ...
Long Path is correct: nobody has a good answer for these situations. If one existed, we'd all be trying to implement it ASAP.
That said, thinking about the several school shootings of the past week or so, a serious discussion of school security and safety is needed, just as a serious reappraisal of airport security was needed in the wake of 9/11. It needs to be addressed, although I confess I haven't the foggiest idea about how to proceed except to rule out one of the more obvious suggestions.
CCW in schools - not going to happen. Just look at the ruckus caused by placing armed individuals on airliners after 9/11. It strikes me as distinctly ludicrous to believe that a few school shootings suddenly is going to alter public opinion drastically to allow faculty and school staff to carry weapons of any sort. Railing on about how custodians and teachers should be allowed to carry, that one of them could have stopped any of these incidents as easily as they might intercept boys smoking in the bathroom (and nobody should pretend for a second that they know what exactly happened in those classrooms), not only is a waste of time on an argument that has no realistic hope of winning, IMHO, but probably will be seen as an attempt to capitalize on a tragedy to advocate a political agenda, regardless of the truth of the charge and regardless of what 'the other side' does. Many parents do not trust teachers now: what possibly makes you think they will allow them to be armed?
Rather, trying to allow teachers and school staff to CCW probably will be seen as a weak political play, and one that will only serve to paint gun owners as fringe advocates of radical and dangerous ideas, not realistic solutions to a real problem (again, regardless of the correctness of that assessment). It marginalizes us in a way I don't think most of us want to be marginalized. Jokes about liberals whining about evil guns and "It's for the children!" are self-serving at best - it is about guns and it is about children in the public view, and frankly in reality. If gun owners want to see their rights protected, then they need to be seen as part of the solution, and part of a real-world solution that doesn't involve allowing the gym teacher to pack a .45, precisely because those people packing the .45's are seen in many quarters as contributing to the problem with their insistence on their rights above perceived threats to the public safety. If gun owners are not seen as part of the solution, they will be seen as part of them problem, or rather, they will continue to be seen as part of the problem.
Probably an unpopular opinion, but it's how I see it. Like I said, I don't have a clue about how to solve this problem, but it is a problem, and answers that center on guns, in either direction, probably will lead down roads nobody here wants to travel.
BTW, I'm no Amish expert here, but many of them do own guns, primarily for hunting.