Tex. Loc. Gov't Code § 382.106
A county may authorize the board to adopt rules:
(3) to provide for public safety and security in the district.
Transferred from Local Government Code, Subchapter C, Chapter 372 and amended by Acts 2009, 81st Leg., R.S., Ch. 87 (S.B. 1969), Sec. 15.009, eff. September 1, 2009.