WASHINGTON -- U.S. special forces seized a "key leader" of the 2012 attack that killed a U.S. ambassador and three other Americans in Benghazi, Libya, and he is on his way to face trial in the U.S., the Obama administration announced Tuesday.

President Barack Obama said the capture Sunday of Ahmed Abu Khattala sends a clear message to the world that "when Americans are attacked, no matter how long it takes, we will find those responsible and we will bring them to justice."

"We will find you," Obama declared.

As recently as last August, though, Abu Khattala said in media interviews that he was not in hiding nor had he been questioned by Libyan authorities about the attack at the diplomatic compound. He denied involvement and said he had abandoned the militia.

A witness interviewed after the Benghazi attack said Abu Khattala was present and directing fighters. Abu Khattala admitted being there but said he was helping rescue trapped people.

Administration officials said Tuesday that despite his media interviews, he "evaded capture" until this weekend, when military special forces, including members of the Army's elite Delta Force and the FBI, nabbed him. No shots were fired, no civilians were hurt and no one else was taken into custody in a surprise raid, officials said.

Abu Khattala was headed for the United States to face what Obama called "the full weight of the American justice system." Obama called the Libyan a suspected "key leader" of the attack.

U.S. officials said Abu Khattala was being held on the Navy amphibious transport dock ship USS New York, which was in the Mediterranean Sea. The officials spoke only on condition of anonymity because they weren't authorized to discuss Abu Khattala's whereabouts.

A Benghazi native in his early 40s, Abu Khattala spent much of his adult life jailed by former Libyan ruler Moammar Gadhafi for his involvement in Islamist movements.

During the 2011 uprising against Gadhafi, he became a military leader, forming the small Islamist militia called the Abu Obaida bin Jarrah Brigade -- a group that gained notoriety for its reported involvement in the killing of rival rebel leader Abdul Fattah Younis. He also is accused of being a senior leader of the Benghazi branch of Ansar al-Shariah in Libya, a militia that espouses an extremely conservative Salafist strain of Islam. The U.S. has designated it a terror group.

Abu Khattala has always denied involvement in the Benghazi attack, but U.S. officials have repeatedly pointed the finger at him and Ansar al-Shariah. In August, the U.S. attorney's office for the District of Columbia filed charges against him.

As for the circumstances of Abu Khattala's capture, Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, credited U.S. forces with "carrying out a dangerous and complex capture operation resulting in no casualties."

The Pentagon press secretary, Navy Rear Adm. John Kirby, said that regardless of how openly the Libyan was said to have been living, the important point was that he now is in custody.

"Let's just say for argument's sake he was living in plain sight; he's not anymore," Kirby said. People should not think this was a situation where "he was going to McDonald's for milkshakes every Friday night and we could have just picked him up in a taxicab," he said. "These people deliberately try to evade capture."

On Capitol Hill, Republicans urged the administration to get as much intelligence out of Abu Khattala as possible before anyone reads him his rights to remain silent, supplies him with a lawyer or prepares him for trial in a U.S. courtroom.

Sen. Saxby Chambliss of Georgia, top Republican on the Intelligence Committee, said interrogation of the Libyan already was underway and "we hope to find out some positive things."

Abu Khattala is charged with terror-related crimes in U.S. District Court in Washington and will be tried like a civilian, the administration said. The Obama administration policy is to treat terror suspects as criminals when possible and not send them to the U.S. military prison in Guantanamo Bay, Cuba, like hundreds of terror suspects captured during the administration of President George W. Bush.

Republican Senate leader Mitch McConnell of Kentucky said the U.S. should skip the legal niceties and focus on interrogation.

"The most valuable thing we can get from this terrorist is information about who else was involved in this," McConnell said. "We'll be watching closely to see how much information they glean from him and how they're handling it."

Sen. Lindsey Graham, R-S.C., added: "We should have some quality time with this guy -- weeks and months. Don't torture him; have some quality time with him."

Justice Department spokesman Marc Raimondi declined to comment on whether Abu Khattala had been read his Miranda warning, a statement read to U.S. criminal suspects before they are questioned to preserve the admissibility of their statements in court.

"As a general rule, the government will always seek to elicit all actionable intelligence and information we can from terrorist suspects in our custody," Raimondi said in an email.

The Sept. 11, 2012, attack in Benghazi killed U.S. Ambassador J. Christopher Stevens and three other Americans. Stevens was the first U.S. ambassador to be killed in the line of duty in more than 30 years.

According to a criminal complaint unsealed Tuesday, Abu Khattala is charged with killing a person in the course of an attack on a federal facility and conspiring to do so; providing, attempting and conspiring to provide material support to terrorists that resulted in death; and discharging, brandishing, using, carrying and possessing a firearm during a crime of violence.

Officials said he could face the death penalty if convicted of the first charge.

"Even as we begin the process of putting Khattala on trial and seeking his conviction before a jury, our investigation will remain ongoing as we work to identify and arrest any co-conspirators," Attorney General Eric Holder said Tuesday.

FBI Director James Comey, speaking in Minnesota, said Abu Khattala's arrest sends a message to others who need to be held accountable that "we will shrink the world to bring you to justice."

Some Republicans said Abu Khattala should be headed for Guantanamo so that he could be interrogated at length.

"The president is more focused on his legacy of closing Guantanamo Bay than preventing future terrorist attacks like what happened in Benghazi," said Sen. Jim Inhofe, R-Okla.

Senate Judiciary Committee Chairman Patrick Leahy, D-Vt., countered that Abu Khattala can be brought to justice in U.S. courts "just as we have successfully tried more than 500 terrorism suspects since 9/11." He said sending the Libyan to Guantanamo would be taking "the easy way out."

National Security Council spokesman Caitlin Hayden said in an emailed statement: "We have not added a single person to the GTMO population since President Obama took office, and we have had substantial success delivering swift justice to terrorists through our federal court system."

Since the Benghazi attack, which fell on the 11th anniversary of the Sept. 11, 2001, attacks in the United States, Benghazi has become a fixture of angry political debate in Washington.

With the 2012 presidential election near, Republicans accused the White House of intentionally misleading voters about what sparked the attack by portraying it as one of the many protests over an anti-Muslim video made in America, instead of a calculated terrorist attack on the president's watch.

Republicans, not satisfied with the results of a series of earlier hearings and reports on the attack, including inquiries by three congressional committees, this year formed a House select committee to continue the investigation.

Obama, for his part, accused the Republicans of politicizing a national tragedy.

Democrats point to a series of reports and inquiries to say that Susan Rice, then-ambassador to the United Nations, had acted in good faith when she portrayed the attack as a response to the anti-Muslim video; that the security of the small mission in Benghazi had been appropriately handled by lower-level State Department officials; and that the United States had no military means to halt the attack once it was underway.

A commission led by Thomas Pickering, a respected diplomat, and Adm. Mike Mullen, the former chairman of the Joint Chiefs of Staff, found "systemic failures" and "management deficiencies" by State Department officials in protecting the Benghazi outpost, but uncovered no evidence of the sort of administration cover-up that some Republicans have alleged.

Information for this article was contributed by Lolita C. Baldor, Nancy Benac, Robert Burns, Julie Pace, Donna Cassata, Eric Tucker, Maggie Michael, Sarah El Deeb and Amy Forliti of The Associated Press; by Adam Taylor of The Washington Post; and by David D. Kirkpatrick, Eric Schmitt, Michael D. Shear, Brian Knowlton from and Rick Gladstone of The New York Times.

A Section on 06/18/2014