Sources : Five Blackwater guards charged in 2007 fire that killed 17 people . Sixth suspect in plea negotiations , whereabouts unknown . Charges are not publicly known because indictment is under way . Charges could be made public as early as Monday .
Sources : Five Blackwater guards charged in 2007 shooting that killed 17 Iraqis . Sixth guard in plea negotiations , sources say . Charges are not publicly known because indictment is under seal . Charges could be made public as early as Monday .