In the last scheduled pre-trial hearing for alleged al-Qaeda operative known as Anas al-Libi, the defendant took the witness stand on Wednesday to contest the United States government’s claim that he knowingly and voluntarily waived his right to remain silent during his first hours in FBI custody.

Al-Libi, a 50-year-old Libyan whose legal name is Nazi Abdul al-Ruqai, testified before U.S. District Judge Lewis Kaplan in an evidentiary hearing tightly focused on the moments following al-Libi’s transfer on October 12, 2013, from military to civilian custody.

Given the situation, “I couldn’t concentrate on anything,” al-Libi told the court through an Arabic translator. When asked by his attorney, Bernard Kleinman, why he signed the papers waving his Miranda rights and paving the way for an FBI interview, al-Libi said, “You have no choice but to sign it.”

Al-Libi and his co-defendant, Khaled al Fawwaz, are among 26 defendants, including now-dead al-Qaeda leader Osama bin Laden and his fugitive successor Ayman al-Zawahiri, listed in the al-Qaeda terror conspiracy indictment brought by the U.S. government after the 1998 truck bombings of U.S. embassies in Kenya and Tanzania that killed 224 people, including 12 Americans. A 2001 trial already sent four defendants to life imprisonment for that attack.

Prosecutors have portrayed al-Libi, al Fawazz, and a third defendant, Adel Abdel Bary, as key members of al-Qaeda’s UK cell in the 1990s. Abdel Bary pleaded guilty last month and faces sentencing in January. Jury selection in the al-Libi and al Fawwaz trial begins Nov. 3.

Al-Libi’s transfer into the hands of the FBI and federal prosecutors for the Southern District of New York followed a week in CIA custody aboard an American warship, the USS San Antonio, in the Mediterranean Sea. Al-Libi was brought to the ship after U.S. special operations forces famously snatched him from a Tripoli street as he was returning home from a mosque on Oct. 5, 2013. During his week aboard the San Antonio, Al-Libi endured “countless hours of aggressive interrogation,” along with sleep deprivation and isolation in a cold room with no furniture, according to the motion to suppress al-Libi’s post-arrest statements filed by Kleinman.

Al-Libi — who has been treated for hepatitis C and liver cirrhosis, and went on hunger strike while in CIA custody — lay blindfolded and handcuffed in a hospital gurney as he was flown from the ship by helicopter to Aviano Air Base, Italy. From there, he was taken on a seven-hour flight aboard a U.S. Air Force plane to Stewart Air National Guard Base roughly an hour north of New York City. Al-Libi told the court today that, at first, he did not know where the plane was headed.

“I thought it was Guantanamo,” he testified.

NYPD detective turned SDNY investigator George Corey described the airborne interrogation he conducted with FBI Special Agent Philip Swabsin and the assistance of an Arabic translator. Corey sat on a crate two feet away from and facing al-Libi, who sat reclining in an aisle seat.

“I told him at this point he was under arrest, and I was taking him to New York,” said Corey in response to questioning by Assistant US Attorney Adam Fee. No threats, no yelling, no brandishing of weapons; a conversation between men, he said.

Today’s appearance marks the third time this year Corey testified about an airborne interrogation of an important terrorism suspect. He played the same role in the prosecutions of one-time al Qaeda propagandist Suleiman Abu Ghaith and radical imam Mustafa Kamel Mustafa, better known as Abu Hamza.

Corey emphasized that his interrogation of al-Libi was free from CIA influence or involvement, saying that in the days before al-Libi’s capture and transfer, he and Swabsin blocked work emails from certain senders, stopped logging onto a classified computer network, and didn’t go to their regular offices to avoid learning anything about the CIA interrogation of al-Libi.

“This is a new interview, and that whatever he said previously has nothing to do with what we will discuss here,” Corey testified he told al-Libi. “He asked if we were taking him to a military court or criminal court.”

Although al-Libi was tired and “upset with the way he was captured. . . . He was responsive,” said Corey. “He was listening.”

Crucially, it was clear that, based on his answers, al-Libi understood the questions he was asked by the interrogators, Corey testified. When it came to the Miranda rights waiver signed by al-Libi, translator Nehad Abusuneima read it out loud aboard the plane, in Arabic, according to Corey.

Previous statements “will not be useable against you in a U.S. court,” states the English version of the waiver. “Anything you say now can be used against you in court.”

Al-Libi initialed each paragraph, writing “NR” 13 times on the Arabic version, including next to the statements: “I am willing to make a statement and answer questions” and “I do not want a lawyer at this time.”

Then he signed his full name at the bottom of the form. The airborne questioning would go on for an hour, then a break, until the flight landed, and al-Libi was admitted under a pseudonym to Westchester Medical Center in Valhalla, NY. Corey and Swabsin visited him the next day.

“He was happy to see us, it appeared,” Corey testified. “He had [sic] thanked us for treating him with dignity and respect.” However, al-Libi told the law enforcement officials he wanted an attorney and to stop talking, Corey said, adding that he never spoke to the defendant again.

When al-Libi was called to the stand today, he walked haltingly, wearing the standard issue navy blue uniform of the Manhattan Correctional Center. Fifteen years after he was indicted, he looks as if someone pasted a salt-and-pepper beard and mustache on his old FBI Most Wanted photo.

Al-Libi, a college-educated computer engineer who lived in England for several years, asserted to Judge Kaplan that he told Corey and Swabsin on the plane that he wanted an attorney. “But they continued,” he said.

Swabsin, a 17 year FBI veteran, did not testify at today’s hearing. He assisted the prosecution of Ahmed Khalfan Ghailani who was convicted in a 2010 jury trial for his role in the East Africa embassy bombings. Ghailani is serving a life sentence imposed by Judge Kaplan.

We’ll have to wait until the trial to see the substance of Swabsin’s report on his airborne interrogation of al-Libi, unless Judge Kaplan decides to suppress the defendant’s statements.

An earlier version of this post spelled al-Libi’s legal name, Nazi Abdul al-Raghie.