Death ensuing from efforts to disperse unlawful assemblies or riots—If, by reason of any of the efforts made by any 2 or more of the said magistrates or officers, or by their direction, to disperse such unlawful, riotous or tumultuous assembly, or to seize and secure the persons composing the same, who have refused to disperse though the number remaining may be less than 12, any such person, or any other person there present as spectators or otherwise, shall be killed or wounded, the said magistrates and officers and all persons assisting by their order, or under their direction, shall be held guiltless and fully justified in law; and if any of the said magistrates or officers, or any person acting by their order, or under their direction, shall be killed or wounded, all the persons so unlawfully, riotously or tumultuously assembled, and all other persons who, when commanded or required, shall have refused to aid or assist the said magistrates or officers, shall be held answerable therefor.