In this subchapter:
(1) "County officer" means a sheriff, county tax assessor-collector, county clerk, district clerk, county treasurer, county auditor, or county purchasing agent. The term does not include a county officer as defined by Section 159.002.
(2) "Precinct officer" means a constable.
(3) "County judicial officer" means a justice of the peace or a master, magistrate, or referee appointed by a justice of the peace.
(4) "County employee" does not include a person covered by Subdivision (1), (2), or (3).