The prohibitions of Section 9.20.020 shall not apply to the use of any gun or instrument by:
A. A law enforcement officer or other duly authorized public official or employee in the performance of any official duty;
B. Any person to whom a license, permit or authority is issued by the chief of police of the city for the use of such gun or instrument for a valid and proper purpose and for use in a manner not likely to harm any person, animal or property;
C. Any person when used only for the necessary protection of property, habitation or person in a manner authorized by the laws of the state under or within rights guaranteed by the constitution of the state or the United States of America.
(Prior code § 12-1-26(B))