Prosecutors at the Sept. 11 war crimes tribunal at Guantanamo Bay want 10 people who lost relatives in the terrorist attack to testify before the long-stalled case goes to trial.

Federal prosecutor Ed Ryan asked the judge at a hearing Tuesday to allow the family members to testify in October at the U.S. base in Cuba. Ryan says they are important witnesses but are sick or elderly and may not be available when the death penalty trial finally starts in 2017 at the earliest.

The family members would testify about the loss of their sons and daughters during the Sept. 11, 2001, terrorist attack and its effect on their own lives.

Defense lawyers say public depositions will taint the potential military jury pool and should be done in private.