They also have jurisdiction over the George Washington Parkway adjacent to Reagan National Airport, the US Park Police notwithstanding. They are exceedingly well-trained and have been good hosts re: providing firing range access, supervision, and training to us near Dulles for Boy Scout marksmanship activities.
They can and have overruled the TSA clowns if need be and are the designated first responders for virtually all incidents at Dulles which are not clearly under the jurisdiction of US Customs (now called ICE). FBI/SWAT is called in if an aircraft is commandeered or attacked, and FBI and/or ICE generally take over custody of perps if other Federal laws are involved.
I'm glad that the Dulles police nailed this guy as opposed to one of his fellow feds.......