Reuters reports today that as chief plotter Khalid Sheikh Mohammed and other 9/11 defendants, it is not clear whether inculpatory statements made by the defendants will be admissible into evidence at their trials or which statements prosecutors will seek to introduce. Since many defendants will likely allege such statements were only made as a result of physical coercion, they provide a very shaky foundation for major prosecutions. (In Sheikh Mohammed's case, however, finding public inculpatory statements should not be difficult).
As Daniel noted a few weeks ago, one of the six defendants the prosecution had initially sought to try jointly, Mohammed al-Qhatani, has already been separated for trial purposes and some commentators conjecture it had to do with particular flaws in the evidence against him. In Al-Qhatani's case, the presiding judge refused the charges against the man who is accused of plotting to serve as the 20th 9/11 hijacker without prejudice, so the government may refile the charges at any time.
Arraignments are scheduled for Thursday, June 5, but it is very unlikely that either the prosecution's strategy or the standards the judges will apply in determining which inculpatory statements to admit into evidence will be clarified at that time.