Miss. Code Ann. § 65-1-136

(1) In addition to employing security officers as full-time employees of the Mississippi Department of Transportation as authorized under subsection (1) of Section 65-1-131 , the Mississippi Transportation Commission may contract with any private security firm or business authorized to do business in this state for the purpose of providing security for buildings, property or facilities owned by or under the jurisdiction of the Transportation Commission or the Transportation Department, or for buildings, property or facilities located on a trunkline highway at or near a point of entry into this state in which a welcome center or hospitality station has been established by the Mississippi Department of Economic and Community Development.

(2) A security officer of a security firm or business with which the commission has contracted pursuant to the provisions of this section, while engaged in the performance of his duties, shall carry on his person a badge identifying him as a security officer and an identification card issued by the Transportation Commission. When in uniform, each such security officer shall wear his badge in plain view.

(3) A security officer of a security firm or business with which the commission has contracted pursuant to the provisions of this section shall have only such powers of arrest as may be exercised by a private citizen of this state and only such right to bear firearms or weapons while engaged in the performance of his duties as authorized under Section 97-37-7 .