Alexandria, Va. ? The Bush administration soon must decide whether it wants to move the case of Sept. 11 conspiracy suspect Zacarias Moussaoui to a military tribunal, where it would be easier to keep national security information secret.

The case has reached a crucial stage, because U.S. District Judge Leonie Brinkema is making decisions on sensitive testimony the government says could affect national security.

With jury selection set for May 27 and a trial date of June 30, unresolved questions of national security could cause more delays in the drawn-out proceedings.

Here are some questions and answers about the case:

Q: What is the pressing issue on witness testimony?

A: Brinkema has ruled secretly that Moussaoui may have access to a suspected al-Qaida mastermind, Ramzi Binalshibh. The government may not want his statements admitted in a public trial.

Q: What does access mean?

A: It is not clear whether the judge would allow direct questioning of Binalshibh, access to his statements to interrogators or some other type of access such as a video hookup.

Q: What advantage would the government have in a military tribunal?

A: Tribunal rules under consideration would provide more secrecy and fewer rights for the accused than trials in the civilian court system. The trials would be for non-U.S. citizens. The government could keep a suspected terrorist from testifying or at least keep the statements secret.

Q: Why, then, doesn’t the administration simply dismiss the criminal charges and move the case to a tribunal?

A: The Justice Department wanted to demonstrate it could handle a sensitive, post-Sept. 11 terrorism case under the criminal justice system. Atty. Gen. John Ashcroft has said he wanted to move ahead with a criminal trial.

Q: Is the Binalshibh issue important beyond the Moussaoui case?

A: Yes. It could set a precedent that would govern testimony by suspected terrorists in criminal trials. The ruling could determine whether the Justice Department would send future terrorism cases for noncitizens to military tribunals.