key points , barbara starr reports. >> reporter: they all cautioned this is the early picture in - and the investigation continues. the pentagon is looking at exact circumstances. the entire team led by has been interviewed officials say when they last saw johnson. the u.s. team stopped on the nigeria, mali border so they could pick up supplies and food and water and they met with village elders. investigators believe that ambush may have begun when u.s. soldiers were back in their vehicle, possibly even driving. those killed are laid to rest, defense secretary james mattis on capitol hill briefed senator