In the face of rampant skepticism, ISIS has now provided photographic evidence it was behind the massacre at a Moscow concert hall. The attack occurred on Friday evening, with gunmen entering the Crocus City Hall with AK-style weapons and explosives. Terrifying videos of the ordeal were made public showing people being gunned down in cold blood as others hid behind barriers. Russian FSB forces eventually arrived with the building already in flames. (WARNING: GRAPHIC) Watch Video HERE CLICK ABOVE ARTICLE LINK FOR THE VIDEO Within hours ISIS put out a statement of responsibility through its propaganda outlet, Amaq News Agency....