An image grab taken from a video released by the Islamic State (IS) and identified by private terrorism monitor SITE Intelligence Group on September 2, 2014 purportedly shows a masked militant holding a knife and gesturing as he speaks to the camera in a desert landscape before beheading 31-year-old US freelance writer Steven Sotloff. The United States has identified the masked Islamic State militant who murdered Sotloff and US journalist James Foley in separate videotaped beheadings, FBI chief James Comey said on September 25, 2014. "We believe we have identified the executioner," Comey told reporters at a briefing in Washington. "I won't tell you who it is." AFP PHOTO / SITE INTELLIGENCE GROUP / HO === RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / HO / SITE INTELLIGENCE GROUP - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS FROM ALTERNATIVE SOURCES, AFP IS NOT RESPONSIBLE FOR ANY DIGITAL ALTERATIONS TO THE PICTURE'S ===
