Get rid of the gimmick rounds in your shotgun -- the rubber and bird. It should only have buck shot or slugs. Gimmick rounds 1) will not stop someone, and 2) may indicate to a court that you fired it without being in fear for your life.
You may not legally fire ANY firearm at someone, regardless of the ammunition used, unless the situation is so dire that you believe one of you is going to die, and you have decided that it will be him instead of you.
Also, file a police report with all the information you have that they have not yet been written down by the officers, as, if anything ever happens, it will be beneficial to have prior documentation of events.