An alleged al-Qaida member who was snatched off the streets in Libya and interrogated for a week aboard an American warship pleaded not guilty to bombing-related charges Tuesday in a case that has renewed the debate over how quickly terrorism suspects should be turned over to the U.S. courts.

Despite calls from Republicans in Congress to send him to Guantanamo Bay for indefinite interrogation, Abu Anas al-Libi became the latest alleged terrorist to face civilian prosecution in federal court in New York, the scene of several such convictions.

Al-Libi, wearing a thick gray beard, looked frail and moved slowly as he was led into the heavily guarded courtroom in handcuffs. An attorney said he had come to court from a New York hospital, where he was treated for three days for hepatitis C and swollen limbs.

The 49-year-old al-Libi was captured by American commandos during an Oct. 5 military raid in Libya and questioned for a week aboard the USS San Antonio.

He was indicted more than a decade ago in the twin 1998 bombings at the U.S. embassies in Kenya and Tanzania that killed 224 people, including a dozen Americans. If convicted, he faces life behind bars.

Known as one of al-Qaida’s early computer experts, al-Libi is accused of helping plan and conduct surveillance for the attacks. He is believed to have used an early-generation Apple computer to assemble surveillance photographs.

The defendant kept his hands folded on his lap as the judge read the charges in a courtroom secured by about a dozen deputy U.S. marshals. The judge ordered him detained after a federal prosecutor called him a “clear danger.”

Republicans stepped up their criticism of Obama for his administration’s handling of al-Libi, saying he should have been sent to the American prison at Guantanamo Bay for more interrogation instead of being taken to the U.S. and given access to civilian courts and the legal protections they provide.

“He was a treasure trove of information,” said Sen. Lindsey Graham of South Carolina.

“The most dangerous thing we could do as a nation is to treat a captured al-Qaida terrorist as a common criminal, read them their Miranda rights and put them in civilian court before we have a chance to gather intelligence.”

New York Republican Rep. Peter King, a member of the House Intelligence Committee, said: “The real issue is the intelligence. Once he gets a lawyer, he holds the cards. … Put it this way: Now he decides whether he will talk.”

Democratic Sen. Patrick Leahy of Vermont defended the administration, saying dozens of terrorists have been arrested and continued providing information.

“Wouldn’t it be nice if we demonstrated to the rest of the world that we’re not afraid of these people, that we have the best court systems in the world and we’re going to use them?” he said.

Al-Libi’s family and former associates have denied he was ever a member of al-Qaida.

“The presumption of innocence is not a small technicality here,” his court-appointed attorney, David Patton, said in email sent after the hearing. In a 150-page indictment, al-Libi “is mentioned in a mere three paragraphs relating to conduct in 1993 and 1994 and nothing since. … There is no allegation that he had any connection to al-Qaida after 1994, and he is eager to move forward with the legal process in this case.”

Al-Libi’s lawyer also said the defendant goes by the name Nazih Abdul-Hamed al-Ruqai.

The prosecution in the United States is in keeping with a policy of bringing suspected al-Qaida sympathizers and operatives to civilian courts rather than military tribunals.