Supreme Court Won't Revive 9/11 Plea Deals That Spared the Death Penalty

The US Supreme Court declined on Monday to hear a bid by Khalid Sheikh Mohammed, the accused mastermind of the September 11, 2001 attacks, to revive a 2024 plea agreement that would have spared him the death penalty in exchange for a guilty plea. The deal was scrapped by former Defense Secretary Lloyd Austin.

The justices turned away appeals by Mohammed and two co-defendants who had also signed plea agreements, Mustafa al Hawsawi and Walid bin 'Atash. Their appeals challenged a lower court ruling that upheld Austin's decision to void the deals. The US Court of Appeals for the District of Columbia Circuit rejected an argument that Austin, who served under former President Joe Biden, had acted too late.

Bloomberg Law reported the court gave no explanation in turning away the appeals. The Supreme Court's action is the latest step in a military prosecution of detainees held at Guantanamo Bay, Cuba, that has faced two decades of legal gridlock.

What happens next

The decision puts the case back in the hands of the military courts. In August, a US Air Force judge set the trial for June 2028. CNN legal analyst Steve Vladeck, who filed a brief urging the justices to take the appeals, said the denials clear the way for pretrial proceedings to continue, but even the summer 2028 trial date looks unrealistic given the issues that remain, CNN reported.

USA Today reported another obstacle for the prosecution. In August, a military judge threw out Mohammed's confession to FBI agents, ruling it was not given voluntarily and cannot be used at trial. Prosecutors had already agreed to exclude statements Mohammed made in CIA custody. They had hoped his admissions to a clean team of FBI agents would be admitted. The judge's decision removes what prosecutors have called the centerpiece of their case.

A case stuck for a quarter century

Mohammed is the best known inmate at Guantanamo. The facility was set up in 2002 by then President George W. Bush to house foreign terrorism suspects after the September 11 attacks, which killed nearly 3,000 people. Mohammed is accused of orchestrating the plot to fly hijacked passenger jets into the World Trade Center in New York City and into the Pentagon in Arlington, Virginia.

The plea agreements had been offered and accepted by the US official overseeing the Pentagon's Guantanamo war court, and drew criticism from Republican lawmakers. Austin revoked the deals two days later. A military judge later ruled that Austin lacked authority to invalidate them. That ruling was upheld in December by the US Court of Military Commission Review. The District of Columbia Circuit paused the proceedings and, in July 2025, backed the decision to scrap the deals in a 2 to 1 vote, saying Austin indisputably had legal authority to withdraw.

Defense lawyers for Mohammed and al Hawsawi, including lawyers from the American Civil Liberties Union, urged the Supreme Court to hear the case. They said Austin's action violated controlling military law and prolonged the best chance for finality in the September 11 case in a quarter century. The agreements had also prompted a backlash from some groups representing September 11 victims and their families, CNN reported. USA Today reported that Peaceful Tomorrows, a group founded by family members of victims, urged the court to put the plea agreement back in place, while the Justice Department said families are divided over the death penalty and the choice should rest with an official who answers to the public.