Go have a look at this item at Michelle Malkin's place.
I will not greatly dwell on the propriety of the subject matter of the photograph in question. Suffice to say that I could draw the proper distinctions in my sleep.
What is important to understand about this is that it is the actual, practical, policy of the school administration to not draw ethical distinctions. The whole objection of the school administration is to moral evaluations, per se, although only down to the level of applied violence. (They are making their own moral evaluation over the matter of applied violence, but that's where it stops. This is like actively refusing to consider the difference between drinking from a sewer or a pure spring.)
The individual student involved looks, so far as I can see from here, strong enough to -- maybe -- sort out the difference between, say, her brother and some animal on the street with a gun in his hand and murder in his heart. However, this is a very long bet when it comes to the prospect of a budding mind. People at that age positively require ethical guidance in such things, and that guidance can be consequential to statements and events that people who draw such arbitrary lines as that in this case do not think about when they commit them. (And this is the most charitable face that can be put on the thing: "Forgive them, for they know not what they do.") Simply put: it is in no way impossible that children will draw all the wrong conclusions from things that they see going on around them.
In this entire context, there is nothing in the world surprising to me when a fifteen year-old gives free rein to every irrational passion of his age, and goes nuts with a firearm.
It's because he has been actively taught -- in myriad ways -- to not consider anything about acts like that from a rational ethics. He has been taught to not think.
Ayn Rand once pointed out, "Man is the only creature that can sink below his nature."
It is not astonishing what comes next after that happens.