EDS NOTE: GRAPHIC CONTENT – This undated image shows a frame from a video released Friday, Oct. 3, 2014, by Islamic State militants that purports to show the killing of journalist Alan Henning by the militant group. Internet video released Friday purports to show an Islamic State group fighter beheading British hostage Alan Henning and threatening yet another American captive, the fourth such killing carried out by the extremist group now targeted in U.S.-led airstrikes. (AP Photo) ONLINE OUT