army staff sergeant accused of the unthinkable. walking off base and executing 16 civilians, nine of them children. the sergeant is a qualified sniper trained to hit and kill people at a distance of eight football fields. let s go to chris lawrence. what else do we know about this accused gunman? he s a combat veteran that did three tours in iraq. on the last tour in 2010, his vehicle rolled over. he suffered a traumatic brain injury. the army treated him for that. he was diagnosed and declared fit for duty. he s a married man, a father of two. over the weekend, the military moved his family, his wife and kids on to the military base in the state of washington for their own protection. now, as to what happened here, he left the base, his combat outpost at 3:00 in the morning. the afghan guards noticed he was gone. noticed him leaving. they called their american counter parts. it raised alarms. the americans put a search party together to search for the soldier. at the same