Operation Pastorius, Nellie Bly, Boston Strangler

The National Firearms Museum in Fairfax, Virginia displays a pistol that once belonged to members of a secret network of wartime spies that plotted against America on its very own soil. At The Newseum in Washington, D.C., visitors can discover a bag that belonged to a pioneering journalist whose groundbreaking investigation generated more than headlines. And at the Museum of Crime and Punishment a switchblade tells the tale of an infamous murderer whose mysterious identity still haunts the city of Boston.For even more Mysteries at the Museum, head to discovery+. Go to discoveryplus.com/mystery to start your 7-day free trial today. Terms apply.