Ahmed Abu Khattala, the accused leader of the 2012 attack on the U.S. Embassy in Benghazi, Libya made his first appearance in a U.S. courtroom Saturday in Washington, pleading not guilty to criminal charges related to the embassy attack.

The attack killed four Americans, including Ambassador John Christopher Stevens. Abu Khattala was flown in to Washington via helicopter from the USS New York, where he was being held since his capture earlier in June. Abu Khattala was captured by U.S. Special Operations forces working with the FBI in Libya in an operation that reportedly took a month of planning. Fox News reported Abu Khattala was taken by surprise and "didn't know what hit him."

Senator Kelly Ayotte, R-N.H., expressed concern  the handling of Abu Khattala runs the risk of losing “critical intelligence” in the War on Terror.

"Abu Khattala is a 'Specially Designated Global Terrorist' who is a leader of a designated Foreign Terrorist Organization responsible for the deaths of four Americans,” Ayotte’s statement read. “I have serious concerns that conducting a rushed interrogation on board a ship and then turning Khattala over to our civilian courts risks losing critical intelligence that could lead us to other terrorists or prevent future attacks. I've asked the Defense and Justice departments for an update on his status, including whether he has been told he has the right to remain silent."

President Obama’s decision not to send Khattala to Guantanamo Bay Detention Center and instead try him in the United States sparked ire amongst conservative lawmakers like Sen. John McCain, R-Ariz., and Representative Lindsey Graham, R-S.C.

President Obama called Khattala's capture a demonstration the United States "will do whatever it takes to see that justice is done when people harm Americans."

"We will continue our efforts to bring to justice those who were responsible for the Benghazi attacks," Obama continued.

The FBI says documents regarding Abu Khattala's case would be made available following the hearing.