Need info about zero tolerance policies in schools?

Hi, I'm doing a research paper on zero tolerance policies in schools located in the NYC metropolitan area. I'm trying to get more info on the types of zero tolerance policies...so far i know there is a policy for drugs and another policy for weapons. Is there any good sites that can aid me in my search? Any other help would be great (e.g. books, news articles). I've done some of the research myself already, it's just that I'm not finished yet.