The 30-minute hearing was von Brunn's first public appearance since the shooting. The Washington federal court hearing had been delayed several times as von Brunn recovered in a hospital after being shot by other museum guards.
Von Brunn appeared to be wearing medical bracelets. Although he had no visible wounds or bandages, the injuries make it difficult for him to hear and speak, his attorney said. He wore navy a D.C. jail uniform and looked mostly at his lap, leaning over at times to speak with his lawyer.
Von Brunn first shook his head and then called out "your honor" when the judge suggested he was going to order an evaluation. His attorney and the judge tried to advise him not to speak.
"Your constitution guarantees me a speedy and fair trial," von Brunn finally said in a halting voice.
"I'm a United States citizen, and as a U.S. naval officer I swore to protect my country. I take my vows very seriously," said von Brunn, a World War II veteran who served on a patrol boat.
In asking that von Brunn not be released, prosecutor Nicole Waid said von Brunn's actions were clear on videotape.
"This isn't a case of whodunit, your honor," Waid said.
She said that though von Brunn may appear frail, he is still a danger because he "has no true friends" and "nothing to lose."
Waid said that von Brunn arranged his finances and funeral plans before his "suicide mission" at the museum, and that he wanted to kill as many people as possible.
He shook his head when Waid recounted how he had once tried to kidnap members of the Federal Reserve board. He was caught outside a board meeting carrying a bag stuffed with weapons. He describes his attempt with apparent pride on his Web site. He was sentenced in 1983 to more than four years in prison for attempted armed kidnapping and other charges in his Fed assault. He was released in 1989.
Von Brunn was indicted in July on charges including first-degree murder for the death of museum guard Stephen T. Johns, who was black. Four of the charges carry a possible death penalty if he's convicted.
Public records show that in 2004 and 2005 he lived briefly in Hayden Lake, Idaho, which for years was home to the Aryan Nations, a racist group run by neo-Nazi Richard Butler. He had a racist, anti-Semitic 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.