A US military judge has set a 5 June 2028 trial date for Khalid Sheikh Mohammed and three others accused of plotting the 11 September 2001 attacks.Mohammed was considered one of Al-Qaeda leader Osama bin Laden’s top lieutenants before he was captured in March 2003 in Pakistan.The date is 18 months later than prosecutors requested, allowing more time to resolve pretrial disputes, including over what evidence can be presented.US authorities have spent more than two decades trying to bring the case to trial. The 2028 date could still be delayed if pretrial deadlines are not met. A previous trial scheduled for 2021 was cancelled.Mohammed is accused of developing and directing the plot to hijack passenger planes and crash them into the World Trade Center and the Pentagon. A fourth hijacked plane crashed into a field in Pennsylvania. The attacks killed nearly 3,000 people.The failed plea dealMohammed faces trial alongside three alleged accomplices – Walid bin Attash, Ali Abdul Aziz Ali and Mustafa al-Hawsawi – who are accused of helping organise or facilitate the attacks.A federal appeals court last year rejected a plea deal that would have allowed Mohammed to plead guilty and avoid the possibility of execution.The agreement would have given Mohammed and two co-defendants life sentences without parole and required them to answer questions from victims’ families. The Biden administration later rejected the deal after two years of negotiations.A key legal issue has been whether the defendants can receive a fair trial after being tortured in CIA custody. The plea deal would have avoided some of those disputes.Mohammed and his three alleged accomplices are among the last detainees held at the US military base at Guantanamo Bay, Cuba.The facility held roughly 800 prisoners at its peak, but they have since slowly been sent to other countries. A small fraction of that number remain.