Tex. Loc. Gov't Code § 143.105
In addition to meeting the eligibility requirements prescribed by Section 143.023, to be certified as eligible for a beginning position with a police department, a person must be at least 21 years of age at the end of the probationary period and have:
(3) been employed full-time for at least five years as a peace officer licensed by:
Acts 1987, 70th Leg., ch. 149, Sec. 1, eff. Sept. 1, 1987.
Acts 2007, 80th Leg., R.S., Ch. 84 (S.B. 342), Sec. 1, eff. September 1, 2007.
Acts 2009, 81st Leg., R.S., Ch. 611 (H.B. 780), Sec. 1, eff. September 1, 2009.
Acts 2013, 83rd Leg., R.S., Ch. 93 (S.B. 686), Sec. 2.52, eff. May 18, 2013.