A judge says that the self-described mastermind of the September 11th attacks cannot testify in the trial of Osama bin Laden's son-in-law.
Khalid Sheikh Mohammed is currently being detained at Guantanamo Bay.
Defense attorneys for Sulaiman Abu Ghaith wanted Mohammed to testify in court on behalf of their client, but a federal judge has denied that request.
Abu Ghaith is married to Osama bin Laden's daughter and had served as an al-Qaida spokesman.
He is on trial in the city on charges he conspired to kill Americans.