SEC. 9. Whoever shall fire a gun or pistol in said city, shall be fined therefor in any sum not exceeding fifty dollars: Provided, That such penalty for shooting shall not apply to military companies, while performing military duty, or to any police officer or officers while in discharge of any duty in pursuance of any ordinance of said city, or in obedience to any law of the State of Indiana; or to any person who may fire any gun or pistol in or upon his own premises, except where the ball or shot shall pass beyond the limits of said premises, or in defense of his or her life, liberty or property, or when attacked by any vicious animal.