cnn.com (CNN) -- John Walker, the American captured while fighting alongside the Taliban in Afghanistan, arrived on U.S. soil Wednesday evening to face trial and a possible sentence of life in prison if convicted. Walker was accompanied by FBI agents aboard a military cargo plane from Kandahar, Afghanistan. He was turned over to the U.S. Marshals Service when the plane landed at Washington-Dulles International Airport in Virginia. Walker, 20, of California, was scheduled to make his first court appearance at 9 a.m. Thursday in U.S. District Court in Alexandria, Virginia, court officials told CNN. He faces four criminal counts, including engaging in a conspiracy to kill U.S. nationals abroad and providing material support to terrorists. He could face life imprisonment if convicted. He has allegedly said that Osama bin Laden thanked him personally for joining the jihad. Walker was expected to be housed at the Alexandria Detention Center because there is no similar federal facility in northern Virginia. The same facility near the courthouse holds Zacarias Moussaoui, the first suspect charged in the September 11 terrorist attacks. QUICKVOTE Do you think the detainees in Cuba are being treated humanely? Yes No View Results CNN.COM SPECIAL REPORT VIDEO/AUDIO John Walker returning to U.S. N.Y. 'most prepared' city MORE STORIES Arroyo wins backing for Abu Sayyaf hunt Terror suspect charged in Spain Report: Al Qaeda detainee revealed embassy plot John Walker expected to arrive Wednesday in U.S. EXTRA INFORMATION Crashes in aerial offensive Conditions at Camp X-Ray Defending Guantanamo RESOURCES CH-53E Message board A Walker family spokesman said his parents are in Washington anxiously waiting to meet with their son.