Army specialist ivan lopezs life inside out looking for what brought him on post with his own private mission to kill. Were learning too about how the shootings unfolded moment by moment and how the aftermath is being so very deeply felt in the fort hood extended family. Lets go first to justice correspondent pamela brown with the latest on the investigation. Pamela, the big question tonight is one of motive. What are we learning about the why . Why ivan lopez went on this rampage . Reporter that is the big question, john. Investigators still trying to figure out what the trigger was. But were learning from sources that theyre looking into whether he was angry over canceled leave, looking into whether that might have played a role. General milley spoke here earlier today, general at fort hood, said there was a possible verbal altercation between lopez and another soldier right before the shooting happened. So theyre looking at that as well. General milley making it clear here that lope