An Army National Guardsman who wanted to join the Islamic State was arrested along with his cousin.
The detailed public examination highlighted the agency’s successes and limitations.
A case discussing the covert operation could complicate nuclear talks with Iran, officials said.
Intelligence officials suspect Robert Levinson was abducted by Iran during a visit to the island of Kish.
As part of the deal, the former CIA director acknowledges improperly handling classified material.
Liban Mohamed was taken into custody shortly after the FBI announced a reward for information.
The man responsible for beheading Islamic State hostages had long-standing ties to extremist groups.
Friends identified the man who beheaded Western hostages as Mohammed Emwazi, born in Kuwait.
A review of U.S. procedures aims to end interagency confusion that has led to heartache as families await word on loved ones captured overseas. However, the no-ransom policy is unlikely to change.
Officials say they are unsure of how Kayla Mueller died.