John Walker Lindh's battle has moved from Afghanistan to a U.S. courtroom, where his lawyers will challenge the government's use of the Taliban soldier's statements to the FBI.

But Walker's attorneys will find it difficult to invalidate the personal account he gave investigators Dec. 9 and 10 about his time with the Taliban, legal experts said Thursday.

While the defense contends Walker asked for a lawyer starting Dec. 2, the government has a paper he signed that waived legal representation when the FBI interviewed him.

"I think it will be admissible," said Robert Precht, director of the Office of Public Service at the University of Michigan law school. Precht, who represented a defendant convicted in the 1993 World Trade Center bombing, called the defense challenge "a big charade" and predicted the defense eventually would negotiate a plea bargain.

E. Lawrence Barcella Jr., who prosecuted terrorism cases as an assistant U.S. attorney, said, however, the defense has raised a legitimate question by asserting that Walker asked for a lawyer before making his statements.

"The focus is whether he gave a knowing waiver of a constitutional right," Barcella said. "Once a suspect in custody asks for a lawyer, the questioning is supposed to cease."

In Walker's Dec. 9 and 10 statements, he told the FBI he met in a small group with Usama bin Laden, that he understood bin Laden ordered the Sept. 11 attacks and that more attacks would follow.

Walker made his first court appearance Thursday looking more like the crewcut, clean-shaven kid next door than the long-haired Taliban fighter with a full beard that has been pictured in widely published photographs of his capture in Afghanistan. He told a U.S. magistrate judge in a 15-minute hearing that he understood the charges, which could bring him life imprisonment.

He was accused in a criminal complaint of conspiring to kill Americans abroad; providing material support and resources to bin Laden's Al Qaeda group and a second terrorist organization; and contributing goods and services to the Taliban and to people whose property was legally blocked in the war against terrorism.

Walker's next court appearance was set for Feb. 6, partly to determine whether he will remain in federal custody pending trial. If there is no grand jury indictment by that date, the government would be obligated to present some evidence that Walker likely committed a crime.

The legal experts said the government may have to show that Walker, who was wounded, was not on medication that impaired his thinking when he signed the waiver. It also would be relevant to know what government agents said to him during the two weeks he was a captive prior to the FBI visit.

"If it's a fact that he asked for a lawyer and then a statement was taken without a lawyer, the rules would prohibit introduction of that statement," said Lloyd Weinreb, professor of criminal law at Harvard University. "But I could imagine a case where a person says he wants to talk to a lawyer and then says 'I changed my mind, I want to tell you something.'"

Michael Nardotti, a former judge advocate general for the Army, said the defense could argue that Lindh should have been provided a lawyer upon request — even while in military custody — since he later became a civilian defendant.

The government would argue he was picked up as an enemy soldier and it would be permissible to treat him like all other captives — including interrogation without a lawyer.

Nardotti said he was unaware of a previous case where a captured enemy soldier was turned over to the civilian justice system.

Walker's "chances of succeeding are very small" in making the case that the FBI interview should not be used, said Ronald Rotunda, a law professor at the University of Illinois. "If he can show that's not his signature or that he was beaten over the head and tortured until he signed it, that's obviously a different case."

The waiver that Walker signed "is very strong testimony against any self-serving claims that he makes now," said Richard Uviller, a law professor at Columbia University.