In the climax to one of my stories, a student goes on a shooting rampage in her school. Another character, portrayed earlier in the story as a drug dealer who frequently comes to school armed because of the large amounts of money she often carries, produces a gun of her own and takes down the mad shooter before she can harm any more students.
The trouble is that I do not know what legal ramifications would apply to the girl who shot down the mad shooter. From what I understand, the drug-dealer could be charged with possession of a weapon on school grounds . . . but these charges might be overthrown given that she used the gun in self-defence. Also, and I don't know if this would come into the matter or not, the mad shooter is not herself killed by the drug-dealer. (The drug-dealing aspect will not come into play at any time.)
I'm not looking for a great amount of legal details--there's not going to be a huge trial-scene or anything--just enough to tell the reader what eventually became of the drug-dealing girl. I realise these laws might vary from state to state, but since this story is pretty much set in Anywhereville, USA, I really just need a blanket that might apply anywhere in America.