For those interested in examining “terrorist attacks committed on American soil” and hate crimes, the Crime Museum in Washington, D.C., is the place to be starting on Wednesday. In addition to offering information on recent attacks, the museum's "Domestic Terrorism and Hate Crimes" exhibit will display objects from the wrenching incidents. From the 2013 Boston Marathon bombing, for example, there will be a runner’s medal and a bib from one of the victims. Letters from the Unabomber, Ted Kaczynski, will also be on display, as will a Virginia Jihad Network rifle that was confiscated in 2003. The exhibit will also...