WASHINGTON (AP) — Defense Department will object military judge’s decision Plea agreements reached by Khalid Sheikh Mohammed, the alleged mastermind of the Sept. 11, 2001 attacks, and two other defendants are valid, a defense official said Saturday.

The decision taken last week overruled Defense Secretary Lloyd Austin’s decision. to cancel deals and concluded that the plea agreements were valid. The judge granted three motions for criminal charges and said he would set them at a later date to be determined by the military commission.

The department will also seek a postponement of any hearing on the plea, according to the official, who was not authorized to discuss legal matters publicly and spoke on condition of anonymity. Attorney General Rear Admiral Aaron Rugh sent a letter to families of 9/11 victims on Friday informing them of the decision.

Judge Air Force Col. Matthew McCall’s decision allowed the three 9/11 defendants to plead guilty in a U.S. military courtroom at Guantanamo Bay, Cuba, sparing them from the risk of the death penalty. The pleas from Mohammed, Walid bin Attash and Mustafa al-Hawsavi would be an important step towards closing a long-running and legally troubled government investigation into the attacks that killed nearly 3,000 people.

Government prosecutors had negotiated the agreements with defense attorneys under government auspices, and the top official of the military commission at Guantanamo had approved the agreements. But when the agreements were made public this summer, they were immediately criticized by Republican lawmakers and others.

Within days, Austin issued an order saying he would nullify them. He said plea bargaining in potential death penalty cases linked to one of the most serious crimes committed on U.S. soil is a crucial step that should be decided solely by the secretary of defense.

The judge had ruled that Austin did not have the legal authority to revoke the plea agreements.

The agreements and Austin’s attempt to overturn them constituted one of the most alarming cases in the United States, fraught with investigation delays and legal challenges. This includes years of pretrial hearings to determine the admissibility of defendants’ statements about torture they suffered in CIA custody.

While the families of some of the victims and others are determined that 9/11 investigations should continue through to trial and possible death sentences, legal experts say it is not clear whether that will happen. If the 9/11 cases clear the hurdles to trials, verdicts, and sentences, the U.S. Court of Appeals for the District of Columbia Circuit will likely hear most of the issues during any death penalty appeal.

The issues include the CIA’s destruction of interrogation videos, whether rescinding Austin’s plea deal constituted unlawful interference and whether the torture of the men tainted subsequent interrogations by nonviolent “clean squads” of FBI agents.