Texas Code of Criminal Procedure - CRIM P Art. 45.201. Municipal Prosecutions

(a) All prosecutions in a municipal court shall be conducted by the city attorney of the municipality or by a deputy city attorney.

(b) The county attorney of the county in which the municipality is situated may, if the county attorney so desires, also represent the state in such prosecutions. In such cases, the county attorney is not entitled to receive any fees or other compensation for those services.

(c) With the consent of the county attorney, appeals from municipal court to a county court, county court at law, or any appellate court may be prosecuted by the city attorney or a deputy city attorney.

(d) It is the primary duty of a municipal prosecutor not to convict, but to see that justice is done.