The man behind Wednesday's deadly shooting at Fort Hood had mental health issues and was being treated for depression and anxiety before he killed three people and wounded 16 others.
Hours after the shooter opened fire, U.S. Rep. Michael McCaul of Texas identified the suspected gunman as Spc. Ivan Lopez. However, officials did not say what might have motivated him to kill fellow soldiers and then himself.
"We do know that this soldier had behavioral health and mental health issues and was being treated for that," said Lt. Gen. Mark Milley, head of the Army's III Corps at the Texas post.
Lopez was being evaluated for post-traumatic stress disorder, but had not yet been diagnosed for the illness.
Milley said Army officials were waiting to notify the man's family of his death before they released his name.
In addition to being examined for signs of PTSD, the soldier was undergoing treatment for depression, anxiety and a "variety" of other issues, Milley said.
Lopez, who was on medication, served four months in Iraq in 2011 and had "self-diagnosed" a traumatic brain injury. "He was not wounded in action," Milley said.
Lopez arrived at the installation in February from another Army post and had not been assigned to one of the Army Wounded Transition Units, military units that are set up to care for wounded, injured or ill soldiers. Those assigned to these units have case managers who help them track appointments and manage their medical treatments.
Investigators are checking into whether Lopez had a criminal history, trying to learn more about the state of his mental health and his experiences in combat. There was no evidence that the shooting was terrorism related but nothing is being ruled out, Milley said.
"All the things that you would expect us to be doing are being done right now," he added late Wednesday.
The soldier, who was armed with a .45-caliber Smith & Wesson handgun, was married and "does have family," Milley said. The family lives in the Fort Hood area, he said.
Milley said the shooter, whom he did not name, walked into a building on the base and opened fire, then got into a car, fired more shots and then went to another building shooting before he was engaged by responding military police.
All those wounded and killed were military personnel.
A female soldier encountered the shooter in a parking lot, Milley said.
Lopez, dressed in combat fatigues, reached to pull out his weapon from under his jacket. The female soldier then pulled out her gun and "engaged" from about 20 feet away. Lopez then put the gun to his head and fired.
Lopez was assigned to the 13th Sustainment Command (Expeditionary).
Fort Hood was the post where 13 died and more than 30 were wounded in the deadliest domestic military attack in U.S. history.
Army psychiatrist Nidal Hasan was convicted and sentenced to death last year in the Nov. 5, 2009, attack there on his fellow soldiers as they waited inside a crowded building.
Contributing: Gregg Zoroya, Gwen Flanders, David Teeuwen, Cooper Allen, William Welch