Heidi Beirich of the Southern Poverty Law Center says the SPLC had been tracking James von Brunn's involvement with right-wing extremists, including neo-Nazis and white supremacists, since the 1970s. (Update: Here's SPLC's blog post on von Brunn. --Jed)
Update:The White House reacts:
White House spokesman Robert Gibbs said in his regular briefing today that President Obama is "saddened" by reports of a shooting at the Holocaust Museum in Washington D.C. and is monitoring the situation as it develops.
"Not too long before coming out here, probably about 1:55 or so, [I] had an opportunity to speak with the president about the shooting at the Holocaust Museum today, informed him of the situation, gave him the details that we had been given via the Situation Room," Gibbs said. "He asked about the condition of the security guard."
Asked about White House involvement in the situation, Gibbs said the White House is "in contact with and get updates from Homeland Security Council and other agencies like the FBI."
CNN is reporting that a news conference will be starting momentarily - use this as a live thread. - BarbinMD
Update: CNN is reporting that a guard at the museum has died. No further details. - BarbinMD