Update 4:20 P.M.
D.C. police say a Holocaust Museum guard, Stephen Tyrone Johns, and the alleged shooter, James von Brunn, were rushed to George Washington University Hospital.
Police have now confirmed that Johns has died.
Police say Alexis "Lexi" Lynn Johnson, 6, was kidnapped by her mother's ex-boyfriend
23-year-old was using the social media app Periscope as she allegedly drove drunk in Lakeland, Florida