Lawyers for John Walker Lindh say he didn't get legal help when he wanted it. But a piece of paper he signed undercuts those claims, some legal experts say.

Part of Walker's defense strategy turns on a judge agreeing that he was denied an attorney before talking to the FBI in December — and that a jury should not be told about any damaging comments he might have made at that time.

"His 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."

Walker's lawyers plan to argue that he asked for a lawyer after he was captured near the northern Afghan city of Mazar-e-Sharif following an uprising by Taliban and Al Qaeda prisoners.

After Walker's first court appearance Thursday, lawyer James Brosnahan said, "From Dec. 2, John Lindh asked for a lawyer, repeatedly asked for a lawyer."

Attorney General John Ashcroft said Walker, 20, signed a statement waiving his right to an attorney before he spoke to the FBI on Dec. 9 and 10.

"The district court judge will have to decide who to believe," said Anne Bowen Poulin, a professor at Villanova University School of Law. "It's a swearing contest between him [Walker] and whoever the government brings in. The judge would have to conclude that they are lying, and judges don't like to do that."

Similar defense strategies are often used in criminal cases, but not usually with success.

Walker is facing various charges, including conspiring to kill Americans outside the United States. He is accused of supporting Usama bin Laden's Al Qaeda terrorist organization.

Walker had no attorney and was recovering from a battle wound when he talked to the FBI.

Justice Department officials refused to release a copy of paperwork Thursday that they say he signed. The FBI contends he was informed of his constitutional rights to have a lawyer and avoid self-incrimination, and that he signed a form acknowledging that.

"That piece of paper that he signed is very strong testimony against any self-serving claims that he makes now," said Richard Uviller, a law professor at Columbia.