Sotloff fixer Yosef Sotloff says U.S. officials never interviewed him about Sotloff . ISIS says it `` is actively investigating the savage murder of Sotloff Abobaker says masked ISIS gunmen outnumbered him , Sotloff , three armed guards . `` I know all the roads . Abobaker believes a border guard informed ISIS about Abobaker 's location .
Sotloff fixer Yosef Sotloff says U.S. officials never interviewed him about Sotloff . ISIS says it `` is actively investigating the savage murder of Sotloff Abobaker says masked ISIS gunmen outnumbered him , Sotloff , three armed guards . Abobaker believes a border guard informed ISIS about Abobaker 's location .