In this subchapter:
(1) "Head of a law enforcement agency" means the highest-ranking peace officer in a law enforcement agency, including the director, sheriff, constable, or police chief, as applicable.
(2) "Law enforcement agency" means an office, department, or other division of this state or a political subdivision of this state, including a county, municipality, school district, or hospital district, that is authorized by law to employ peace officers.