"He's not going to be the star witness for the prosecution," Gordon said. "If the prosecution's case depended on Malvo, the case would not be strong at all."

Malvo told mental health experts for his defense that he was the shooter in two slayings, the experts testified in his 2003 trial. Those were the killing in Washington state of the niece of a woman who testified against Muhammad in a bitter custody dispute with his ex-wife, and Conrad E. Johnson, the Fort Washington bus driver who became the final sniper victim on Oct. 22, 2002 as he prepared to start his bus route in Montgomery County.

But he told investigators that he carried out almost all the sniper shootings.

Lawyers said Malvo could be an effective, if eerie, witness for the prosecution, even if Muhammad asks him about his inconsistent statements.

"It's going to be mighty weird, mighty goddamned weird," to have Muhammad question Malvo, said Michael S. Arif, one of two lawyers who headed Malvo's defense in Virginia.

He said he would worry about what Malvo would say. "Nobody knows what is going to come out of this kid's mouth. He could say, 'I shot everyone,' " Arif said. "He has nothing to lose."

Although Malvo never took the stand against Muhammad, jurors in Malvo's 2003 Virginia trial heard a tape-recording made by police in which a smug and snickering Malvo confessed and toyed with interrogators, boasting of his shooting prowess and declaring that he wanted to plunge America into a state of "martial law" during the sniper rampage.

In that audiotape, Malvo laughed and said he had no remorse for the shootings. He said the shootings were aimed at creating such turmoil that government officials would give in to the pair's demands for $10 million.

After predicting that Muhammad would be executed, Malvo said he expected he would face the same fate. "They will kill me too, oh yeah. But they don't have to make a deal. Right now, I incriminate myself."

If Malvo and Montgomery County prosecutors do not reach an agreement, Muhammad cannot force Malvo to speak on his behalf. Malvo would be allowed to protect his right not to incriminate himself, said William R. Blanchard, Malvo's lawyer in Alabama.

Facing inquiries from Muhammad "would probably dredge up some memories that Lee probably would not want to revisit," Blanchard said.

He said he has not been approached about a deal that could include two shootings, one of them fatal, in Alabama.

Jose F. Anderson, a University of Baltimore law professor and defense expert, said that once a defendant represents himself, the entire case becomes unpredictable, including the reactions witnesses have to being questioned by the person who accused them of wrongdoing.

"It's a case-by-case, witness-by-witness adventure," he said.

If Malvo is not called by prosecutors and refuses to testify for Muhammad, it may be possible to get some of his prior inconsistent statements admitted, Anderson said. Inconsistencies, he said, are "one of the greatest things to create doubt in the mind of a juror."

Yesterday, Judge James L. Ryan agreed with prosecutors over Muhammad's objection to allow relatives of victims to listen to testimony in the courtroom. Individual questioning of potential jurors for the trial, expected to last a month, continued. So far, 53 people have been told to return tomorrow for jury selection. A pool of about 60 is needed to select 12 jurors and four alternates. Jury selection is to resume today.