>> this is cell phone video of thursday's shootout. >> reporter: what grabbed the attention of investigators in the mark hassie murder is this, wise county is 100 miles from kaufmann, could he have killed another public servant in texas? seven weeks earlier? >> the fbi is now investigating this case, they want to see if ebol is connect to mark hassie's murder. >> reporter: two public officials gunned down in two states. somebody seemed to be targeting law enforcement at point blank range. coming up: as the investigation grows more urgent, sudden concerns about d.a. mike mcclell mcclelland and cynthia. >> i tried them and didn't get an answer. >> i said, i will go over. >> and then concern becomes alarm. >> at that point, something is really wrong. when "dateline" continues. suffer if there is optionsmebodo