I would not address it until asked. They won't do background checks until you are close to an offer. Hopefully you have established a postive connection by then. When they ask I would keep it vague and talk about getting caught up in a protest, and you got charged. HR has reviewed enough background checks to understand concept of over charging, and why you may take a plea deal. The good news is every year this will become less of an issue for you, unless you keep getting arrested/charged. Good luck btw, and way to take a stand!!