A US military judge has set June 5, 2028, as the new trial date for Khalid Sheikh Mohammed and three co-defendants, extending one of the longest-running terrorism prosecutions in US history.

The long-delayed trial of Khalid Sheikh Mohammed, the alleged mastermind of the September 11, 2001, terrorist attacks, has been pushed back again, with a US military judge setting June 5, 2028 as the new trial date.

The decision means the case could reach trial nearly 27 years after the 9/11 attacks, which killed almost 3,000 people in the United States. Mohammed and three co-defendants have been held for years while lawyers and prosecutors continue to fight over evidence, interrogation practices and other pretrial issues.

The new date was set by Air Force Lt Col Michael Schrama, the military commissions judge overseeing the proceedings at Guantanamo Bay, Cuba. Prosecutors had sought a January 2027 trial, but the judge concluded that additional time was necessary to address unresolved matters.

Trial Set For 2028

Judge Schrama has scheduled the opening of the trial for June 5, 2028.

The latest timetable represents another delay in a prosecution that has passed through several US administrations and undergone numerous changes in legal strategy and court scheduling.

The defendants were first arraigned in 2008. Their case was later affected by years of legal disputes over evidence gathered during their detention in CIA-run secret facilities.

If the proceedings begin on the new date, almost two decades will have passed since the original arraignment.

Four Men Face Trial

Mohammed is scheduled to stand trial alongside Walid bin Attash, Ali Abdul Aziz Ali and Mustafa Ahmed al-Hawsawi.

All four are being prosecuted under the US military commissions system at Guantanamo Bay.

Prosecutors accuse them of involvement in planning and facilitating the September 11 attacks, in which 19 al-Qaeda hijackers seized four commercial aircraft.

The defendants face charges arising from the attacks, including terrorism and murder-related offences.

Pretrial Disputes Continue

The prosecution has been repeatedly slowed by disputes over evidence and legal procedures.

One of the central issues concerns evidence obtained while the defendants were held in CIA detention facilities, where they were subjected to harsh interrogation methods.

Defence lawyers have argued that statements obtained through coercive treatment should not be admitted as evidence.

Courts have therefore spent years examining the circumstances under which interrogations were conducted and whether information derived from those interrogations can legally be used at trial.

CIA Detention Complicates Case

The defendants' treatment in US custody has become one of the most significant legal complications in the prosecution.

Mohammed and other defendants were held at CIA-operated secret detention sites before being transferred to Guantanamo Bay.

US authorities have acknowledged that detainees were subjected to controversial interrogation techniques, including methods widely criticised as torture.

The defence has argued that these experiences affected the reliability and admissibility of statements obtained during detention.

Prosecutors, meanwhile, have sought to preserve evidence they believe can be used to establish the defendants' roles in the attacks.

Case Spans Multiple Administrations

The 9/11 prosecution has continued through successive US administrations.

The case has experienced changes in prosecutors, defence teams, military judges and proposed trial schedules.

Repeated legal challenges have prevented the proceedings from moving to a full trial, turning the prosecution into one of the most closely watched and prolonged cases arising from the September 11 attacks.

The latest trial date is therefore another attempt by the military commissions system to establish a firm timetable.

September 11 Attacks

The September 11 attacks began on September 11, 2001, when 19 al-Qaeda members hijacked four commercial aircraft.

Two planes were flown into New York City's World Trade Center, destroying the Twin Towers.

A third aircraft struck the Pentagon near Washington, DC.

The fourth plane, United Airlines Flight 93, crashed near Shanksville, Pennsylvania, after passengers attempted to regain control of the aircraft.

Nearly 3,000 people were killed in the attacks, which triggered major changes in US national security, foreign policy and counterterrorism operations.

Why The Delay Matters

The latest postponement highlights the extraordinary difficulty of prosecuting terrorism suspects while ensuring that constitutional and military-commission procedures are followed.

The prosecution must establish its case while the defence continues to challenge evidence linked to years of detention and interrogation.

The passage of time has also created practical problems. Memories fade, witnesses become harder to locate and evidence must be preserved and authenticated decades after the events.

For victims' families, repeated postponements have prolonged the wait for a full judicial proceeding.

What Happens Next

The immediate focus will remain on resolving the outstanding pretrial disputes before June 2028.

Prosecutors and defence lawyers are expected to continue litigating the admissibility of evidence, detention-related issues and other procedural questions before the trial can begin.

If the June 5, 2028 date holds, the opening arguments will come almost 27 years after the attacks and roughly 20 years after the defendants' original arraignment.

The case remains a landmark test for the US military commissions system and for the ability of the American justice system to prosecute the alleged organisers of the country's deadliest terrorist attack.

For now, however, the trial remains more than a year away, and further legal challenges could still affect the timetable.