WASHINGTON -- A gunman identified by authorities as a white supremacist opened fire Wednesday inside the lobby of the U.S. Holocaust Memorial Museum, killing a security guard before being shot and captured.

Federal authorities identified the suspected shooter as James von Brunn, an 88-year-old Annapolis, Md., man with a record of anti-Semitic statements and writings, notably on his Web site. He served more than five years in federal prison on a 1983 conviction for attempting to kidnap members of the Federal Reserve Board,...