Zacarias Moussaoui, the only person prosecuted in connection with the worst terrorist attack in American history, did not get the death penalty because some jurors concluded that he had little to do with Sept. 11. Yet two presumed key planners of the Al Qaeda [9/11] plot, Khalid Shaikh Mohammed and Ramzi Binalshibh, have not been charged, though they have been in U.S. custody for more than three years. A central contradiction in the Bush administration's fight against terrorism is that bit players often have been put on trial, while those thought to have orchestrated the plots have been held in secret for questioning. Current and former intelligence officials have said that the CIA has used aggressive interrogation techniques -- including waterboarding," which makes a suspect feel as if he is drowning -- on captured Al Qaeda leaders. As a result, many legal experts say it may be too late to try Mohammed and Binalshibh in a regular court of law. "They cannot be prosecuted because of the way they have been interrogated," said University of Maryland law professor Michael Greenberger. "They have been subjected to very aggressive questioning, and any statements they made now can't be used against them." An open trial for the Al Qaeda leaders could reveal that U.S. agents used harsh methods, even torture, to extract information, he added. "We have prosecuted a marginal character who appeared unmoored from reality, while the real planners of the crime will not be brought before justice in the United States," Greenberger said.