He indicated he would like to send a message to his family once he had given 'some thought of what I would say.' Told by the reporter he might be able to send an e-mail the next day, Walker said, 'I would appreciate that.' Still other times, the 20-year-old American showed his allegiance to the Islamic state. Referring to jihad, he said, 'It's exactly what I thought it would be.' Asked if it was the right cause, Walker said, 'Definitely.' The American, whose parents live in California, said he was a member of Ansar, or 'helpers,' a group of Arabic-speaking fighters financed by Osama bin Laden. In late November, the fighters agreed to surrender and give up their weapons to the Northern Alliance as part of a deal arranged by Gen. Rashid Dostum, a commander of the anti-Taliban forces.

Walker said he and his comrades walked more than 100 miles to the northern city of Konduz. At one point, when the Ansar fighters were 'in a very bad state psychologically,' Walker said, the Northern Alliance told them to surrender their weapons. To his disbelief, Walker said some fighters hid grenades in their clothes. 'This was all a mistake of a handful of people.' He said trucks carried the men to the compound where the uprising began.

'As soon as I came down from the truck that we had arrived in, a grenade exploded. Someone, I don't know what he was thinking,' Walker said. After the explosion, the authorities put the fighters in a basement at the compound. Eventually, the fighters were allowed to come out one-by-one and searched. 'As they were taking us one-by-one, some of the last people -- again I don't know if they were afraid or whatever -- they did the same thing: They pulled out a grenade and exploded it,' Walker said. 'And so the fighting began.' That is when CIA operative Mike Spann was killed, the first U.

S. combat casualty in Afghanistan. Walker said some of the fighters managed to take control of a storage house filled with heavy weapons. 'I was in the basement the whole time. I didn't see what was going on. I just heard,' he said.

U. S. warplanes struck the compound with bombs and forces fired on the Ansar fighters with guns. Gas was poured into the basement and ignited, killing many of the fighters. Walker said 'freezing water' also flooded the basement, 'drowning the vast majority of us' and leaving the rest in the chilly waters for about 20 hours. As the waters receded, the survivors began discussing surrender.

'It was filled with the stench of bodies and we didn't have any more weapons available. We said, 'Look we " re gonna die,' ' he said. 'If we surrender, the worst that can happen is they " ll torture us or kill us. So right here in the basement, they " re torturing us and killing us, so we might as well surrender.' Toward the end of the interview, the Special Forces medic said, 'He's in a lot better shape than most of them.' He leaned over and told Walker he was a prisoner now. 'A prisoner of Dostum or the Americans?' Walker asked. 'Right now, you are a patient and the Americans are treating you,' the medic said.

Walker is now being held on the USS Peleliu, an amphibious assault ship in the Arabian Sea. The Justice Department is looking at several possible charges that carry the death penalty if proved, including treason and murder of a U. S. government employee, Spann.

'No final decision has been made on this. We " re still looking at all the options,' a law enforcement official told CNN late Wednesday.