A white supremacist shot and killed a guard at the Washington Holocaust Museum on Wednesday near the main entrance. The attacker, armed with a rifle, was wounded.
Police identified the killer as James von Brunn, who previously has served time in jail for felonies.
Visitors to the museum were evacuated immediately after the attack.
The D.C. Holocaust Museum draws over 1.5 million visitors each year. Guards are stationed in front of the museum, and visitors are required to pass through a metal detector. Police who spoke to journalists were not sure if Von Brunn had managed to sneak a gun through the entrance, or if he had opened fire before passing through security.
In July 2006, a gunman opened fire in a Jewish center in Seattle. One woman was murdered and five others were wounded. The gunman, an American Muslim of Pakistani descent, said he carried out the attack because he blamed Jews for the American war in Iraq and subsequent Muslim suffering.