A senior al Qaeda leader accused of participating in the attack on the U.S. embassy in Benghazi, Libya, was arrested in Turkey last month. The Libya-based terrorist leader was transferred to Jordan and subsequently to the U.S., where he is now awaiting trial, according to the Turkish Hurriyet Daily News.

A joint CIA and Turkish intelligence operation led to Abd al-Baset Azzouz’s capture when he attempted to enter Turkey with a fake passport, according to a report from Turkish daily Milliyet. Azzouz is a senior member of al Qaeda’s branch in Libya and allegedly had a role in the bombing that killed U.S. Ambassador to Libya Christopher Stevens and U.S. Foreign Service Information Management Officer Sean Smith on Sept. 11, 2012.

The CIA declined to comment on its alleged involvement in the operation and the Department of Defense did not immediately confirm Azzouz’s continued presence in the U.S.

A man by that name was put on the U.S. State Department’s Designated Terrorist List in September and described as a “key operative capable of training al Qaeda recruits in a variety of skills, such as IED [improvised explosive device] construction.” Azzouz’s name was also presented to the House Committee on Foreign Affairs last year on a list of people it did not “make sense to consider anything but ‘core’ al Qaeda members.” 

Azzouz was detained for nearly 10 months in the U.K. in 2006. Upon his release, he moved to Libya at the request of al Qaeda leader Ayman al-Zawahiri, according to Hurriyet. Al-Zawahiri reportedly sent him to Libya to open a training camp and recruit fighters, a move that “indicates that senior al Qaeda leaders trust him to carry out the strategic task of establishing an al Qaeda network in Libya,” according to a 2012 report from the Federal Research Division of the Library of Congress.

Libyan jihadist group Ansar al-Sharia has been widely held accountable for the deadly Benghazi attack, but the group said in a statement that it "didn't participate as a sole entity." Ansar al-Sharia has a strong presence in Benghazi and is “ideologically aligned” with al Qaeda, according to the State Department. The group also has a branch in the Libyan port city of Derna, where Azzouz allegedly set up his training camp.

Derna has long been a jihadist battleground and is home to several groups, including the Islamic Youth Shura Council, which recently pledged allegiance to the Islamic State group.