They say Semi auto. Look at the safety at 1:15. It does not look like full auto but it is three position.

http://www.khou.com/news/local/hpd-officers-armed-with-ar-15s-at-houston-airports/493724322

Last edited by Armednfree; 11/23/17.
The older I become the more I am convinced that the voice of honor in a man's heart is the voice of GOD.