If an employee of the department commits an assault on an inmate housed in a facility operated by or under contract with the department, the executive director shall file a complaint with the proper official of the county in which the offense occurred. If an employee is charged with an assault described by this section, an inmate or person who was an inmate at the time of the alleged offense may testify in a prosecution of the offense.
Tex. Gov't. Code § 501.002