WASHINGTON — A Libyan militant suspected in the deadly attack on Americans in Benghazi has been captured and is in American custody, the Pentagon said today, marking the first time the U.S. has apprehended one of the alleged perpetrators.

Officials said Ahmed Abu Khattala, a senior leader of the Benghazi branch of the terror group Ansar al-Sharia in Libya, will be tried in U.S. court. He is currently being held in an undisclosed location.

Last year, the U.S. filed charges against Khattala and a number of others in a sealed complaint filed in U.S. District Court in Washington. However, until now, no one had been arrested in the September 2012 attack in which a group of militants set fire to the U.S. diplomatic mission in Benghazi, killing Ambassador Christopher Stevens and three other Americans.

The Obama administration has come under intense criticism from Republicans for being unable to apprehend those responsible for the attack.