A person in possession or control of any building, realty or other premises, or a person who is licensed or privileged to be thereon, is justified in using reasonable and appropriate physical force upon another person when and to the extent that it is reasonably necessary to prevent or terminate what he reasonably believes to be the commission or attempted commission of an unlawful trespass by the other person in or upon the building, realty or premises. (Ord. 2, Series 1991)