White people, especially white officers, and that he was upset about recent police shootings. Just a short time oago, mult pel senior officials said the investigation so far leads them to believe that johnson was, in fact, the lone gunman. He did it by himself. They say the investigation, however, remains fluid. Sources say part of the investigation still includes other possible suspects who may have assisted him. Johnson killed after an hourslong standoff. At this point were waiting for a News Conference from the governor of texas, greg abbott, as well as a number of other folks who will join him. The police chief and mayor will be with him at that press conference. Were expected to get more answers about what happened here. I want to bring in msnbcs tremane lee inside Dallas City Hall where that News Conference is going to be happening, as i understand it, next hour. You spent a better part of the day talking to folks in and around dallas. What are they telling you . Ill tell you wha