By Julia Edwards
WASHINGTON (Reuters) - The U.S. Justice Department is conducting a criminal investigation into the death of American journalist James Foley, Attorney General Eric Holder said on Thursday.
Foley was beheaded by the Islamist militant group Islamic State, an act shown in a video released on Tuesday in which the group called for the United States to end its airstrikes in Iraq. Obama responded that the United States would be relentless in fighting the organization despite the killing.
The identity of Foley's killer, whose face was covered in the video, is unknown.
(Reporting By Julia Edwards; Editing by Susan Heavey)