Trial of Alleged 9/11 Mastermind Set to Begin in 2028 After Nearly Three Decades

The long-delayed trial of Khalid Sheikh Mohammed, the alleged mastermind behind the September 11, 2001, terrorist attacks in the United States, is scheduled to begin in June 2028, nearly 27 years after the deadliest terrorist attack in U.S. history.

According to a scheduling order issued on Wednesday by U.S. Air Force Lieutenant Colonel Michael Schramer, the military tribunal for Mohammed and his three co-defendants will begin on June 5, 2028, at the U.S. military base in Guantanamo Bay, Cuba.

Prosecutors had previously proposed starting the trial in January 2027, but the judge ruled that additional time is needed to resolve pretrial legal disputes and determine which evidence will be admissible in court.

Co-Defendants
Alongside Khalid Sheikh Mohammed, the defendants include:

• Walid bin Attash
• Ali Abdul Aziz Ali
• Mustafa al-Hawsawi

All four men have been detained at the Guantanamo Bay detention facility for years and face charges related to planning and supporting the 9/11 attacks.

Years of Legal Delays
Despite the newly announced schedule, there is no guarantee the trial will begin on time. Previous trial dates—including one set for 2021—were postponed due to ongoing legal challenges.

A major obstacle has been the controversy surrounding the defendants' treatment while in CIA custody. After their capture, they were held in secret detention facilities where they were subjected to interrogation techniques, including waterboarding and other forms of torture. For years, courts have debated whether statements and evidence obtained through those interrogations can be admitted at trial.

Plea Deal Collapsed
In 2024, prosecutors reached a proposed plea agreement under which the defendants would plead guilty in exchange for life imprisonment instead of the death penalty.

However, the agreement was later scrapped following political opposition and objections from the families of many of the victims. As a result, the case returned to the full military trial process.

The 9/11 Attacks
The September 11 attacks involved the hijacking of four commercial airliners by al-Qaeda operatives.

• Two planes crashed into the Twin Towers of the World Trade Center in New York City.
• One aircraft struck the Pentagon near Washington, D.C.
• The fourth plane crashed into a field in Pennsylvania after passengers attempted to overpower the hijackers.
• Nearly 3,000 people were killed in the attacks, making them the deadliest terrorist attacks in U.S. history.

Khalid Sheikh Mohammed and his co-defendants have been in U.S. custody since 2003, yet no final verdict has been reached. The decision to prosecute the case in a special military commission at Guantanamo Bay, rather than in a civilian federal court, has added further legal complexity, with repeated challenges over the tribunal's jurisdiction, procedures, and evidentiary rules.

The prolonged delays have frustrated victims' families, human rights advocates, and legal experts. Many relatives of those killed in the attacks have died before seeing the case come to trial.

If all outstanding pretrial legal issues are resolved as scheduled, the highly anticipated trial is expected to begin on June 5, 2028.