On Monday morning, two days before the 18th anniversary of 9/11, Khalid Sheikh Mohammed, the Pakistani engineer accused of masterminding the attacks on New York City and Washington, D.C., appeared in a Guantánamo Bay courtroom sporting a black turban. Seated near him was his new lead attorney, Gary D. Sowards, a death penalty specialist who represented the Unabomber, Ted Kaczynski; Kaczynski is now serving a life sentence.

In the second row, Mohammed’s co-defendant Walid bin Attash, a native of Yemen, draped a scarf displaying a Palestinian flag over his computer monitor. Rows three to five were occupied by defendants Ramzi bin al-Shibh; Mohammed’s nephew Ammar al-Baluchi; Mustafa al-Hawsawi; and their defense teams.

The word haunting the austere courtroom, and the impending 18th anniversary of the catastrophic attacks, was torture. Thanks to the CIA’s harsh interrogations of Mohammed and his associates, torture has replaced the deaths of 2,976 people as the focus of the quasi-judicial proceedings. Torture not only tormented the perpetrators; it has delayed justice for the victims’ families.

On Monday, nine relatives of 9/11 victims sat behind glass in the back of the high-security courtroom. One by one, they walked up to the window for a closer look at the accused. Media, nongovernmental observers, and military service members filled the seats in the gallery.

The five defendants on trial for planning the attacks listened but did not speak out loud except to acknowledge their voluntary participation in the session. In muted tones, they spoke animatedly with their American lawyers. It was the 38th pretrial hearing in their war crimes trial, and it focused on the prospect of scheduled testimony from FBI witnesses, prompting a series of arguments over which questions can and cannot be asked. Col. W. Shane Cohen, the third judge to preside in this case since the defendants were arraigned on May 5, 2012, recently set a trial date for January 2021.

Late last week, the prosecution sent out a 25-page “classification guidance” revealing a number of new facts that had previously been classified, but also invoking national security restrictions to censor words that had been spoken in prior open or closed sessions. The most startling revelation from this classified document, described in open court by James Connell, attorney for defendant Baluchi, is that FBI agents were detailed to the CIA’s Rendition, Detention, and Interrogation, or RDI, program, a fact that the Senate Intelligence Committee that investigated the programs and produced the 2014 torture report apparently did not know.

By contrast, the torture report said that then-FBI Director Robert Mueller “began seeking direct FBI access to [Mohammed] in order to better understand CIA reporting indicating threats to U.S. cities.” Then-CIA Director George Tenet made “personal commitments … to Director Mueller that access would be forthcoming,” the report noted, but “the CIA’s [Counterterrorism Center] successfully formulated a CIA position whereby the FBI would not be provided access to [Mohammed] until his anticipated transfer to Guantánamo Bay, Cuba,” which did not happen until September 2006.

But according to Connell, the FBI did have access to Mohammed and other black site detainees between 2003 and 2006, when then-President George W. Bush acknowledged the CIA’s secret prisons and brought 14 detainees to Guantánamo to face military tribunals. During that period, Connell said, the FBI sent well over 1,000 questions to the CIA for the agency to ask detainees, including Mohammed, who was subjected to waterboarding 183 times.