A person shall not be employed as a peace officer in the department after attaining sixty-five years of age. [C50, 54, 58, 62, 66, 71, 73, 75, 77, 79, §97A.6(1, b); C81, §80.36 ] 92 Acts, ch 1232, §503 ; 98 Acts, ch 1183, §107 ; 2002 Acts, ch 1135, §1 ; 2005 Acts, ch 35, §20