<Li> The U.S. Park Police helicopter that responded to the Air Florida Flight 90 crash into the Potomac River </Li> <Li> A costume from the 1987 film RoboCop </Li> <Li> A sweat shirt worn by character Jack Bauer in the TV series 24 </Li> <Li> Artifacts of FBI Director J. Edgar Hoover </Li>

When does the national law enforcement museum open