The suspect of the September 11 attacks will appear before a judge after 27 years.

The date on which Halid Şeyh Muhammed, accused of being behind the September 11 attacks that claimed the lives of about 3,000 people in the United States, will be tried has been set. According to a statement from the U.S. military court in Guantanamo Bay, the case will begin on June 5, 2028.

Known also as "KSM," Muhammed was considered one of the most important aides of Al Qaeda leader Osama bin Laden before he was captured. Having received an engineering education, Muhammed was arrested in Pakistan in March 2003. He was then held in CIA‑run clandestine detention centers for three years and was transferred in 2006 to the U.S. naval base in Guantanamo Bay, Cuba.

The trial process has been postponed for years.

The case against Muhammed has remained unresolved for years due to various legal disputes, including how evidence was obtained and the treatment he endured under CIA surveillance.

A deal that would have removed the death penalty from the options in exchange for Muhammed's confession of guilt surfaced last year, but was later withdrawn.

He had said he had planned the attacks from A to Z.

Halid Sheikh Mohammed had said in past statements that he had planned the September 11 attacks "from A to Z".

On September 11, 2001, two of the four hijacked passenger planes struck the Twin Towers of the World Trade Center in New York, one hit the Pentagon near Washington. The fourth plane crashed into a field in Pennsylvania after passengers intervened. Approximately 3,000 people lost their lives in the attacks.

Muhammed also alleged that he helped the 1993 World Trade Center bombing that killed six people and that he was responsible for the murder of American journalist Daniel Pearl in 2002.

He has been held in Guantanamo for more than 20 years.

The United States sent many suspects captured under the "War on Terror" launched after the September 11 attacks to the detention center in Guantanamo. At one point, the facility housed about 800 detainees, most of whom were released or transferred to other countries in subsequent years.

Halid Sheikh Mohammed has been held in Guantanamo since 2006. If the case is filed on the announced date, Mohammed will appear before a judge about 27 years after the September 11 attacks.