James von Brunn died shortly before 1 p.m. at a local hospital in Butner, N.C., said Denise Simmons, the spokeswoman for the federal prison where von Brunn had been held. He had been suffering from chronic congestive heart failure, sepsis and other health problems, she said.
Von Brunn, who faced charges that carried the death penalty, had been receiving medical care for months at the prison complex in Butner, which is known for its medical facilities for aging and sick federal inmates. His lawyer, A.J. Kramer, called the death "a sad end to a tragic situation" and declined to make further comment.
Authorities say von Brunn carried a rifle as he walked up to the U.S. Holocaust Memorial Museum on June 10 and then shot security guard Stephen T. Johns, who was black, as he opened the door for von Brunn. He was wounded by gunfire from two other guards.
Officials at the prison hospital had previously said chronic medical problems had complicated a psychiatric evaluation for the suspect, who prior to the shooting had written racist and anti-Semitic screeds on the Internet.
Officials at the U.S. Holocaust Memorial Museum issued a statement saying their thoughts and prayers remained with Johns' family. "Officer Johns died heroically defending the museum, visitors and staff. This tragedy is a powerful reminder that our cause of fighting hatred remains more urgent than ever," the statement said.
One of the two guards who fired back at von Brunn said he had mixed feelings about his death. "I'm shocked. I'm glad he's gone. I wish he had his day in court, but it'll never come," said Harry Weeks of White Plains, Md.
Weeks returned to work in August and said he thinks often about his slain colleague. "There's not a day that goes by that I don't miss him," Weeks said.
A seven-count indictment against von Brunn charged him with first-degree murder, killing in a federal building and bias-motivated crime. The indictment also accused him of seeking to intimidate Jewish people at the museum.
Von Brunn had a racist Web site and wrote a book titled "Kill the Best Gentiles," alleging a Jewish conspiracy "to destroy the white gene pool." He also claimed the Holocaust was a hoax.