An Iraq War veteran being treated for mental illness opened fire on fellow service members at the Fort Hood military base, killing three people and wounding 16 before committing suicide at the same post where more than a dozen people were slain in a 2009 attack, authorities said.
The shooter apparently walked into a building Wednesday and began firing a .45-caliber semi-automatic pistol that had been purchased recently. He then got into a vehicle and continued firing before entering another building and kept shooting.
He was eventually confronted by military police in a parking lot. As he came within 20 feet (6 meters) of an 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.
The gunman, who was married and served in Iraq for four months in 2011, had sought help for depression, anxiety and other problems. Before the attack, he had been undergoing an assessment to determine whether he had post-traumatic stress disorder, according to Lt. Gen. Mark A. Milley, the senior officer on the base.
The 2009 assault on Fort Hood was the deadliest attack on a domestic military installation in U.S. history. Thirteen people were killed and more than 30 wounded.
The suspect in Wednesday's shooting 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. He did not elaborate.
The gunman was not wounded in action, according to military records, Milley said.
There was no indication the attack was related to terrorism, Milley said.
The military declined to identify the gunman until his family members had been notified. Texas Rep. Michael McCaul, chairman of the House Homeland Security Committee, said the suspect was named Ivan Lopez but offered no other details.
Late on Wednesday, investigators had already started looking into whether the gunman's combat experience caused lingering psychological trauma. Among the possibilities they planned to explore was whether a fight or argument on base triggered the shooting.
''We have to find all those witnesses, the witnesses to every one of those shootings, and find out what his actions were, and what was said to the victims,'' said a federal law enforcement official, speaking on condition