I am so sorry for you, your son, and your family as I am sure this is affecting everyone! What an awful and disturbing note! I agree, you are not overreacting at all......it is the school that is not reacting quick enough! With all of the problems that have occured in schools throughout the nation, it is amazing to me that a school would shrug this off so quickly! I mean the LEAST they could have done was at least notify his teacher so that she could keep a close eye on your boy!
I too would go to the school board and the police. I also would threaten the school that if they do not do something, I would go to the media. Of course, I probably would never actually do that.....but no one likes bad publicity and that might kick their butts into gear! Please keep us updated and I will keep you all in my prayers.