To secure a conviction under s 174(1)(a) of the Criminal Law (Codification and Reform) Act for criminal abuse of duty as a public officer, the State must prove: (1) that the accused is a public officer; (2) that in exercising their functions, they intentionally did something contrary to or inconsistent with their duty; and (3) that this was done for the purpose of showing favour or disfavour to any person. A contravention of administrative by-laws or statutory instruments does not per se constitute criminal abuse of duty under s 174. The prosecution must choose between charging under subsection (a) (doing something contrary to duty) or subsection (b) (omitting to do something) and cannot charge both alternatives simultaneously. Municipal police officers have statutory authority under various legislation to remove vehicles obstructing roads, and exercising such lawful authority does not constitute acting inconsistently with their duties.