U.S. to launch criminal investigation into Foley's execution
The militants said the beheaded was in done in response to recent airstrikes carried out by U.S. forces in Iraq on ISIS targets, in an effort to help Kurdish peshmerga forces.
The militant who appeared in the video of Foley's beheading is believed to be a British national, his identity is also under investigation by the British government.
President Obama on Wednesday addressed the nation, condemning the militants' actions against Foley and promising more air stikes in Iraq.
Speaking of the Islamic extremist group, Obama said ISIS' victims were "overwhelmingly Muslim," and their "ideology...bankrupt."