Summary (tl;dr)

The U.S. Supreme Court has declined to review appeals aiming to reinstate plea deals for Khalid Sheikh Mohammed and two other alleged masterminds of the 9/11 attacks, effectively nullifying agreements that would have spared them the death penalty in exchange for guilty pleas. This decision paves the way for a military trial scheduled for June 2028.

Essential Background

The September 11, 2001, terrorist attacks, which killed nearly 3,000 people, were allegedly orchestrated by Khalid Sheikh Mohammed and his co-defendants. These individuals have been detained at the U.S. military facility in Guantanamo Bay, Cuba, for over two decades, facing charges including conspiracy, murder, terrorism, and hijacking before military commissions. In 2024, plea agreements were reached that would have allowed Mohammed and two co-defendants, Mustafa al Hawsawi and Walid bin 'Atash, to plead guilty to all charges in exchange for life imprisonment rather than facing the death penalty. However, just two days after these deals were accepted by the Pentagon official overseeing the Guantanamo Bay war court, then-Defense Secretary Lloyd Austin revoked them, asserting that a decision on the death penalty for such a grave attack should only be made by the Defense Secretary.

The Full Story

Following Defense Secretary Austin's revocation of the plea deals in 2024, the defendants and their legal teams, including the American Civil Liberties Union, initiated litigation to enforce the agreements, arguing that Austin lacked the authority to invalidate them or acted too late. A military judge initially ruled that Austin lacked the authority, a decision upheld by the U.S. Court of Military Commission Review. However, the U.S. Court of Appeals for the D.C. Circuit subsequently reversed these rulings in July 2025, determining that Austin "indisputably had legal authority to withdraw from the agreements." On October 19, 2026, the U.S. Supreme Court declined to review the D.C. Circuit's decision, thus rejecting the bid to revive the plea deals. This effectively upholds the cancellation of the plea agreements and keeps the death penalty as a potential sentence. As a result, the military trial for Khalid Sheikh Mohammed and his co-defendants has been scheduled to begin in June 2028 at Guantanamo Bay.

Why It Matters

The Supreme Court's denial of the appeals means that the death penalty remains a potential outcome for Khalid Sheikh Mohammed and his co-defendants, a significant aspect for some victims' families who seek full justice. Conversely, defense lawyers and some victims' families expressed concerns that the revocation of the plea deals further delays the long-sought finality in the 9/11 prosecution, which has been mired in legal gridlock for over two decades at Guantanamo Bay. The continued legal process raises questions about the efficiency and fairness of the military commission system. The decision also prolongs the operation of the Guantanamo Bay detention facility, which has been a subject of international debate.

Geographic Location

• Guantanamo Bay, Cuba (detention and military commission proceedings for 9/11 defendants)
• Washington, D.C., District of Columbia, United States (location of the Pentagon where the deals were revoked, the U.S. Court of Appeals for the D.C. Circuit which upheld the revocation, and the Supreme Court which denied appeals)