Texas Transportation Code - TRANSP § 720.001. Badge of Sheriff, Constable, or Deputy

(a) A sheriff, constable, or deputy sheriff or deputy constable may not arrest or accost a person for driving a motor vehicle on a highway in violation of a law relating to motor vehicles unless the sheriff, constable, or deputy displays a badge showing the sheriff's, constable's, or deputy's title.

(b) A person commits an offense if the person violates this section.  An offense under this section is a misdemeanor punishable in the same manner as an offense under Section 86.011, Local Government Code.

(c) An officer charged by law to take or prosecute a complaint under this section shall be removed from office if the officer refuses to do so.