FORT HOOD, Texas - The soldier who killed three people at Fort Hood may have argued with another service member prior to the attack, and investigators believe his unstable mental health contributed to the rampage, authorities said Thursday.
The base's senior officer, Lt. Gen. Mark Milley, said there is a "strong possibility" that Spc. Ivan Lopez had a "verbal altercation" with another soldier or soldiers immediately before Wednesday's shooting, which unfolded on the same Army post that was the scene of an infamous 2009 mass shooting.
However, there's no indication that he targeted specific soldiers, Milley said.
Bob Gordon works on a memorial for the victims of Wednesday's shooting at Fort Hood, Thursday, at Central Christian Church in Killeen, Texas. A soldier opened fire Wednesday on fellow service members at the Fort Hood military base, killing three people and wounding 16 before committing suicide.
Lopez never saw combat during a deployment to Iraq and had shown no apparent risk of violence before the shooting, officials said.
The 34-year-old truck driver from Puerto Rico seemed to have a clean record that showed no ties to extremist groups. But the Army secretary promised that investigators would keep all avenues open in their inquiry of the soldier whose rampage ended only after he fired a final bullet into his own head.
"We're not making any assumptions by that. We're going to keep an open mind and an open investigation. We will go where the facts lead us," Army Secretary John McHugh said, explaining that "possible extremist involvement is still being looked at very, very carefully."
Investigators are looking into Lopez's psychological background. He had sought help for depression, anxiety and other problems, military officials said.
"We have very strong evidence that he had a medical history that indicates unstable psychiatric or psychological condition," Milley said. "We believe that to be a fundamental underlying cause."
Scott & White Memorial Hospital in nearby Temple, Texas, was still caring for five of the 16 people who were wounded. Three were in serious condition, and two others were in good condition and could be discharged later Thursday.
Hospital officials had no information about patients being treated elsewhere, including at a base hospital. But because Scott & White is the area's only trauma center, the patients with the most serious injuries were probably taken there.
Investigators searched the soldier's home Thursday and questioned his wife, Fort Hood spokesman Chris Haug said.
Lopez apparently walked into a building Wednesday and began firing a .45-caliber semi-automatic pistol. He then got into a vehicle and continued firing before entering another building. He was eventually confronted by military police in a parking lot, according to Lt. Gen. Mark Milley, senior officer on the base.
As he came within 20 feet of a police officer, the gunman put his hands up but then reached under his jacket and pulled out his gun. The officer drew her own weapon, and the suspect put his gun to his head and pulled the trigger a final time, Milley said.