The U.S. Justice Department is conducting an investigation into the death of American journalist James Foley by IS militants, Attorney General Eric Holder said on Thursday.
IS released a video on Tuesday of Foley being beheaded by a militant, and threatened to kill another American hostage unless the United Stated ended its airstrikes in Iraq.
"Those who would perpetrate such acts need to understand something," Holder said in a statement. "We have long memories and our reach is very wide and we will not forget what happened. People will be held accountable one way or another."