Among Cooper's notable cases in the U.S. District Court is the criminal case of Ahmed Abu Khattala, who is charged with orchestrating the 2012 Benghazi attack. In a pretrial evidentiary ruling, Cooper denied Khattala's motion to suppress statements he made to FBI agents while detained on the Navy ship USS "New York" en route to the United States, a significant victory for federal prosecutors. Trial began in October 2017.