Khalid Sheikh Mohammed, the self-proclaimed mastermind of the September 11 attacks, will face trial in a court just blocks away from where the World Trade Centre once stood, it was announced today.
The suspect will be transferred from Guantanamo Bay alongside four other detainees accused over the plot, all of whom will now be tried in a civilian federal court in New York, US Attorney General Eric Holder said.
He added that he fully expected prosecutors to seek the death penalty in all five of the cases.
A further five alleged terrorists currently held at the base, including a major suspect in the 2000 bombing of the USS Cole, will face a military trial.
Bringing Mohammed and others to the US to face the legal process is a key part of the White House's plan to close the controversial detention centre in Cuba.
But opponents have argued that treating the men as normal criminal suspects will give them the opportunity to espouse their extremist views in open court.
Speaking in Japan prior to the announcement, President Barack Obama said: "I am absolutely convinced that Khalid Sheikh Mohammed will be subjected to the most exacting demands of justice."
Mohammed has previously admitted to interrogators that he was the architect of the 2001 plot that killed close to 3,000 innocent victims.
It is alleged that he told agents that he suggested the idea to Osama bin Laden as early as 1996. He went on to fund the attacks, train hijackers and oversee the operation, it is claimed.
He will be tried alongside Waleed bin Attash, Ramzi Binalshibh, Mustafa Ahmed al-Hawsawi and Ali Abd al-Aziz Ali.
Those facing prosecution under military law include Abd al-Rahim al-Nashiri, the man prosecutors claim was behind the bombing of the USS Cole in October 2000, killing 17 sailors and injuring many more.
The civilian trials could shed light on some of the interrogation techniques used by US agents at Guantanamo Bay.
It is reported that Mohammad was subjected to waterboarding - the simulated drowning of suspects - 183 times in 2003 before the practice was banned.
Moving the trial to New York is seen by some as a risk on behalf of the US government. Defence lawyers are likely to claim that their defendants are unlikely to get a fair trial in a courtroom so close to the heart of the attacks.
Opponents to the closing of Guantanamo Bay have also said that moving the suspects to US soil puts Americans at greater risk.