10:10 a.m. 4/3 UPDATE: WASHINGTON (AP) -- Army Secretary John McHugh says Fort Hood alleged shooter was deployed for the final months of the Iraq war but did not see combat, was not wounded.
-McHugh says Lopez was examined by a psychiatrist last month and was found to show no violent or suicidal tendencies. He says the soldier had been prescribed Ambien to deal with a sleeping problem.
-McHugh testified Thursday that the soldier appeared to have no connections to extremist groups.
Ivan Lopez enlisted in the Army in June 2008 as an infantryman and later switched his specialty to truck driver, the job he had in Iraq.
FORT HOOD, Texas (AP) -- Authorities say the gunman who opened fire at Fort Hood, killing three people and himself, was an Iraq War veteran being treated for mental illness.
Wednesday's attack also wounded 16 people at the Texas military base, where a 2009 shooting rampage killed 13 people and wounded more than 30. Fort Hood Press Center Web site
The military identified the gunman as Specialist Ivan Lopez. USA Today reports he walked into a building, opened fire, then got into a car and fired more shots.
A federal law enforcement official says investigators will interview his wife, search his home and examine whether his combat experience caused lingering psychological trauma.
The official, who spoke to The Associated Press on condition of anonymity, says investigators also must find witnesses who know what the shooter said and did during the attack.
Fort Hood's senior officer, Lt. Gen. Mark Milley, says Lopez had sought help for depression and anxiety and was being assessed for post-traumatic stress disorder.
Lopez was married and served in Iraq for four months in 2011. He had arrived at Fort Hood in February from another base. He was taking medication and there were reports that he had complained about suffering a traumatic brain injury, Milley said.
The gun, a .45 caliber semi-automatic weapon, had been purchased recently in local area and had not been registered it with the post as required, he added.
Lopez was from the U.S. territory of Puerto Rico and joined the island's National Guard in 1999. He went on a peace and security mission to Egypt's Sinai Peninsula in the mid-2000s, and left the National Guard in 2010 to join the U.S. Army, said Lt. Col. Ruth Diaz, spokeswoman for the Puerto Rico National Guard.
In Washington Wednesday night, Defense Secretary Chuck Hagel issued a statement following news of the shootings.
"Today's shooting was a terrible tragedy for the Fort Hood community, the Department of Defense, and for the nation. My thoughts and prayers are with the victims and their families. And my sympathies go out to this strong and resilient community, which has experienced this kind of senseless violence all too recently. There is nothing more important to us as an institution than the safety and well-being of our people, and for that reason I am grateful to all the first responders who rushed to the scene. We will closely monitor the situation at Fort Hood and stay informed by what investigators and law enforcement personnel learn about the shooting."
KVUE-TV tweets say Thursday that doctors expect most of the survivors of the shooting will be upgraded to fair condition later in the day. Doctors report their injuries range from shrapnel to gunshot wounds to extremities, trunk and neck.