A federal judge ruled Tuesday she was not prejudiced against the man accused of conspiracy in the Sept. 11 attacks and refused Zacarias Moussaoui's request that she dismiss herself from the case.

U.S. District Judge Leonie Brinkema, in a written order, said her description of Moussaoui as "unorthodox" and "unpredictable" represented an accurate reflection of his courtroom conduct.

Moussaoui asked Brinkema to step down in one of six motions he filed Monday and Tuesday, acting as his own lawyer even though the judge has not granted his request to fire his court-appointed attorneys.

Brinkema said Moussaoui must first undergo a mental examination to determine that his mental competence when he made the request. Her order also denied Moussaoui's motion to scrap the exam.

Moussaoui contended the judge's remarks were not the only reason she should disqualify herself. He argued she would not challenge the government's refusal to allow an "open-door" policy on access to documents and he cited her employment 22 years ago at a law firm where Moussaoui's court-appointed public defender, Frank Dunham Jr., was a supervisor.

"Normally, a defendant in a criminal case pleads 'not guilty' at arraignment," Brinkema wrote. "As the record shows, however, at his arraignment, the defendant refused to enter any plea to the charges. Such conduct is unorthodox and suggests that the defendant's behavior in the courtroom may be unpredictable."

Brinkema last January entered an innocent plea for Moussaoui, a French citizen charged with six conspiracy counts. He could face the death penalty if convicted.

In her remarks about Moussaoui's conduct, Brinkema did not mention his 50-minute courtroom speech last week, when the defendant said he prayed for the destruction of the United States and Israel.

The judge said her efforts to manage the trial expeditiously was not evidence of prejudice. She pointed out the court has not been asked to rule on an "open-door" policy for access to government documents.

Brinkema added she had no conflict of interest with the public defender, pointing out Dunham was appointed by the district court's chief judge before the case was assigned to her.