Testing the plan, interagency communications and technology all played a role at the Presidential Inauguration. U.S. Army Staff Sgt. Derrick Brooks and U.S. Navy Yeoman 1st Class Lasean McCray play the role of President-elect Barak Obama and Michelle Obama during the dress rehearsal. Photographs by MC2 David P Coleman and MC1 Daniel J. Calderon

Department of Defense personnel, FBI, Secret Service, TSA agency officers, National Guard members and private security all played a role in protection during the days before and the day of Barak Obama’s inauguration. One of the most important security tests was nine days before the big event, when there was a traditional walkthrough of the swearing in and parade. Private security companies also have a role. "Security was extremely important considering the large crowds and high profile nature of this event," observed Clayton Young, the DC-based general manager for AlliedBarton Security Services. The firm worked in conjunction with the Secret Service, local law enforcement and local groups. Technology also played a part. Alert DC from Cooper Notification allowed officials to communicate emergency information to the public via text messages during the four-day ceremony at the nation’s capitol.