In the shadow of last year’s Boston Marathon bombing, large public gatherings require local law enforcement agencies to shoulder significant security responsibilities, placing high demands on police tactical planning, resources, and budgeting. The sheer number of participants or attendees and the high profile of such events make them potential targets, while simultaneously increasing the challenges faced by law enforcement. For example, the Toyota Grand Prix of Long Beach, California, in April 2013 drew 180,000 spectators. To ensure public safety during this high-profile event, the Long Beach Police Department requested assistance from U.S. Customs and Border Protection (CBP).