the protective services unit (psu) is responsible for providing protective support for the office of the secretary of defense and the chairman and vice chairman of the joint chiefs of staff at the pentagon building. they handle visits to the pentagon by foreign and domestic dignitaries, as well as cover protection for special events on the pentagon reservation, most recently noted the dedication of the 9/11 memorial. the police officers assigned to psu provide residence security in hotels while traveling with hrp's both inside and outside of the united states.