There are roughly 27 law enforcement agencies with overlapping jurisdiction in Washington, D.C. To the casual observer, opportunities for confusion and miscommunication, especially during events like the Navy Yard shooting, probably seem infinite. Yet there were no "mission critical failures" when agencies responded to alleged gunman Aaron Alexis's rampage on September 16, says Chris Geldart, the director of D.C.'s Homeland Security and Emergency Management Agency.
The agencies that initially responded to the Navy Yard shooting—D.C.'s Metropolitan Police Department, the FBI, the National Park Police, and the Capitol Police, among others—worked together almost seamlessly, largely thanks to the amount of time officers spend training with each other. "Not only do you all know the same procedures," Geldart says, "You probably know the guy from the other agency."