A grand jury indictment handed up under seal Thursday and made public Saturday accuses Abu Khattala of participating in a conspiracy to provide material support and resources to terrorists in the attacks of Sept. 11, 2012, that killed U.S. Ambassador Chris Stevens and three other Americans.
That crime is punishable by life in prison. The government said it soon would file more charges against Abu Khattala.
During his initial court appearance, the defendant listened via headphones to a translation of the proceedings. He wore a two-piece black track suit, had a beard and long curly hair, both mostly gray, and kept his hands, which were not handcuffed, behind his back.
He looked impassively at U.S. Magistrate Judge John Facciola for most of the hearing. Abu Khattala's court-appointed lawyer, Michelle Peterson, entered the not guilty plea. Facciola ordered the defendant's continued detention, but the judge did not say where Abu Khattala would be held.
The U.S. Marshals Service said it had taken custody of Abu Khattalah, who now was confined to a detention facility in the capital region, ending a harried day for the Libyan.
U.S. special forces captured Abu Khattala in Libya two weeks ago, marking the first breakthrough in the investigation. Officials had been since been questioning Abu Khattala aboard a Navy amphibious transport dock ship that transported him to the United States.
He was flown early Saturday by military helicopter from a Navy ship to a National Park Service landing pad in the city's Anacostia neighborhood, according to a U.S. official who was not authorized to discuss the transfer publicly and spoke on condition of anonymity.
A U.S. official said Abu Khattala had been advised of his Miranda rights at some point during his trip to the United States and continued talking after that. The official wasn't authorized to discuss an ongoing investigation by name and spoke on condition of anonymity. The nature of those conversations wasn't immediately clear.
A criminal complaint filed last year and unsealed after Abu Khattala's capture charged him with terror-related crimes, including killing a person during an attack on a federal facility. A new, single-count indictment will likely be superseded by additional charges, prosecutors say.
The violence in Libya on the 11th anniversary of the Sept. 11 attacks on the World Trade Center and the Pentagon quickly became a political controversy at home. Republicans accused the White House, as the 2012 presidential election neared, of intentionally misleading the public about what prompted the attacks by portraying it as one of the many protests over an anti-Muslim video made in America, instead of a calculated terrorist attack. The White House said Republicans were politicizing a national tragedy.
The U.S. government accuses Abu Khattala of being a member of the Ansar al-Shariah group, the powerful Islamic militia that officials believe was behind the attack.
A prominent figure in Benghazi's circles of extremists, he was popular among young radicals and lived openly in the eastern Libyan city, where he would be spotted at cafes and other public places even after the Obama administration publicly named him as a suspect in the attacks.
He acknowledged in an interview with The Associated Press in January that he was present during the storming of the U.S. mission in Benghazi. But he denied involvement in the attack, saying he was trying to organize a rescue of trapped people.
During the attack, gunmen fired rocket-propelled grenades and stormed the mission, with many waving the black banners of Ansar al-Shariah.The compound's main building was set ablaze. Stevens suffocated inside and another American was shot dead.
Later in the evening, gunmen attacked and shelled a safe house, killing two more Americans. At the time, several witnesses said they saw Abu Khattala directing fighters at the site.
No evidence has publicly emerged that Abu Khattala was involved in the later attack.
Abu Khattala is one of just a few cases in which the administration has captured a suspected terrorist overseas and interrogated him for intelligence purposes before bringing him to federal court to face charges.
AP National Security Writer Robert Burns contributed to this report.
Justice Department: http://tinyurl.com/m79bngq