Nightly News | April 03, 2014
>> of things happen, people's thoughts turn automatically to the possibility of combat stress. and today we learn more about this gunman's medical record and his military record. our pentagon correspondent, jim miklaszewski , picks up that end of the story. jim, good evening.
>> reporter: brian, defense officials tonight describe 34-year-old specialist ivan lopez as an underachiever who in 15 years of military service went largely unnoticed until now. as a 19-year-old, lopez joined the army national guard in puerto rico . in his hometown today, family friends were shocked by the news. he was a normal kid, always obedient. in 2008 , he signed up for the army infantry at ft. bliss, texas. today lopez was called an experienced soldier.
>> one-year deployment to the sinai with the national guard and a four-month deployment in iraq.
>> reporter: by then, lopez was a truck driver at the end of 2011 . but records show he never saw any action. military officials say, however, that lopez did suffer depression, anxiety and sleep deprivation. but a psychiatric exam at fort hood last month raised no red flags .
>> we have very strong evidence that he had a medical history that indicates unstable psychiatric or psychological condition.
>> reporter: the army was in the process of determining whether lopez suffered posttraumatic stress. up to 20%, 1 in 5 veterans of the wars in iraq and afghanistan, have been diagnosed with ptsd. approximately 300,000 soldiers and marines. but veterans advocates warn, ptsd can be impossible to diagnose.
>> there's not a single thing that we can look for. there's not a single sign that we can examine. it hits different people in different ways.
>> reporter: last week, the iraq and afghanistan veterans of america planted nearly 1,900 flags in washington. but the group's founder insists there their suffering and sacrifice is in no way connected to the events at fort hood .
>> we can't define those veterans by the tragic events of one gunman on a terrible day.
>> reporter: the investigation into what may have driven lopez into this shooting spree has just begun. but military officials already acknowledge they may never find the answer, brian.
>> jim miklaszewski at the pentagon rounding out our coverage of this latest tragedy at fort hood .