Supreme Court Rejects 9/11 Mastermind’s Plea Deal, Keeping Death Penalty on the Table

The U.S. Supreme Court delivered a major setback Monday to accused September 11 mastermind Khalid Sheikh Mohammed, rejecting his attempt to revive a controversial plea agreement that would have spared him the death penalty for his alleged role in the deadliest terrorist attack in American history.

The justices declined to hear appeals from Mohammed and two co-defendants, leaving intact a lower court ruling that allowed the federal government to withdraw from agreements negotiated during the Biden administration.

The decision means Mohammed, along with Walid bin Attash and Mustafa al-Hawsawi, will continue facing prosecution before a military commission at Guantanamo Bay, Cuba, with capital punishment remaining a possible outcome.

The three men are accused of helping organize and carry out the September 11, 2001, terrorist attacks, which killed 2,977 people after hijacked passenger planes struck the World Trade Center and Pentagon, while another crashed in Shanksville, Pennsylvania.

The Supreme Court issued its decision without a detailed explanation. No justices publicly dissented, although Justice Brett Kavanaugh did not participate in the case.

Kavanaugh previously served in the George W. Bush administration during the period when Mohammed was captured in Pakistan in 2003.

The ruling represents another significant development in a prosecution that has remained unresolved for more than two decades, despite the extraordinary scale of the attacks and the international effort to bring those responsible to justice.

Mohammed and his co-defendants reached plea agreements with military prosecutors on July 31, 2024. Under those arrangements, the men would have pleaded guilty to charges connected to the attacks in exchange for life imprisonment without the possibility of parole.

The agreements would have eliminated the possibility of execution, a provision that immediately generated controversy over whether the punishment was appropriate for individuals accused of participating in an attack that killed nearly 3,000 Americans.

The deals were approved by retired Brigadier General Susan Escallier, the senior Pentagon official overseeing military commissions at Guantanamo Bay.

However, then-Defense Secretary Lloyd Austin intervened just days after the agreements were announced, ordering their withdrawal.

Austin maintained that a decision involving the death penalty in a case of such national significance should remain under the authority of the defense secretary.

His intervention triggered a lengthy legal dispute over whether the government could revoke agreements that had already received approval from the military commission’s convening authority.

Attorneys representing Mohammed and the other defendants argued that the agreements were legally binding and that Austin had acted too late to invalidate them.

A military judge initially sided with the defense, concluding that the agreements remained enforceable.

A military appeals court subsequently upheld that determination, creating another obstacle for prosecutors seeking to proceed with the original capital charges.

The federal government then appealed to the U.S. Court of Appeals for the District of Columbia Circuit.

In a divided ruling, the appellate court concluded that Austin possessed the legal authority to withdraw the agreements.

The court rejected arguments that his intervention had occurred too late, allowing prosecutors to resume pursuing the case without the restrictions imposed by the plea arrangements.

Mohammed and his co-defendants appealed that decision to the Supreme Court, seeking to restore the agreements and remove the death penalty from consideration.

Monday’s refusal to hear their appeals leaves the appellate court’s ruling in place.

The Justice Department welcomed the outcome, which preserves the government’s ability to pursue capital punishment if prosecutors secure convictions on the applicable charges.

The decision does not determine the defendants’ guilt or guarantee that any death sentences will be imposed. Those questions remain for the military commission proceedings.

The case has become one of the longest-running and most complicated terrorism prosecutions in American history.

Mohammed, commonly known as KSM, was captured in Pakistan in March 2003 and subsequently held in secret CIA detention facilities before being transferred to Guantanamo Bay in 2006.

He has been identified by American authorities as the principal architect of the September 11 plot, which involved coordinating the hijacking of four commercial airliners and using them as weapons against American targets.

The attacks destroyed the World Trade Center’s Twin Towers, caused extensive damage to the Pentagon and killed passengers and crew members aboard all four aircraft.

Thousands of additional Americans suffered injuries, while families across the country endured the loss of loved ones.

The attacks also prompted sweeping changes in American national security policy, including the creation of the Department of Homeland Security and the launch of military operations against al-Qaeda and the Taliban.

Mohammed has previously acknowledged responsibility for planning the attacks, although the admissibility of statements obtained during his detention has remained a central issue in the prosecution.

Much of the lengthy legal battle has involved disputes over the CIA’s interrogation methods and whether evidence obtained following those interrogations can be presented at trial.

Defense attorneys have challenged the use of statements and other evidence connected to their clients’ treatment while in American custody.

Those disputes have contributed to repeated delays and complicated efforts to bring the defendants before a military commission.

A military judge recently ruled that statements Mohammed made to FBI agents in 2007 could not be admitted as evidence, adding another significant development to the case.

Despite those complications, military officials have now established a tentative trial date of June 5, 2028.

That would place the beginning of the proceedings nearly 27 years after the September 11 attacks.

The proposed plea agreements had also generated disagreement among relatives of the victims.

Some families objected to arrangements that would permanently eliminate the possibility of capital punishment, maintaining that the defendants should face a full trial.

Others viewed guilty pleas and life sentences as a way to obtain a definitive legal resolution after decades of delays and uncertainty.

The Supreme Court’s decision leaves those questions unresolved while allowing the prosecution to continue toward trial.

For the families of the 2,977 people killed on September 11, the case remains an extraordinary example of how long complex terrorism prosecutions can take to reach a conclusion.

The ruling also ensures that one of the most consequential decisions surrounding the case, whether Mohammed and his alleged accomplices could face execution, will not be settled through the withdrawn 2024 agreements.

Instead, prosecutors will continue preparing their case before the military commission, where the defendants face charges that include murder, terrorism and violations of the laws of war.

With the plea agreements no longer enforceable, the legal proceedings will move forward under the original framework, leaving the possibility of the death penalty intact.

More than 25 years after the attacks, the Supreme Court has cleared another legal obstacle in the effort to bring the accused September 11 conspirators to trial.