The father of Spc. Ivan Lopez said Friday that his son "must not have been in his right mind " when he allegedly went on a shooting rampage at Fort Hood, killing three soldiers before turning the pistol on himself.
"This situation has caused great pain," Ivan Lopez Sr. said in a statement issued through family spokesman. "I ask for prayers for the affected families, even more so when there is still an ongoing investigation. My son must not have been in his right mind. He wasn't like that."
The statement released by Giden Lopez Torres, a spokesperson for the Lopez family.
The gunman who opened fired at several locations on the sprawling U.S. Army base in central Texas killed three soldiers and wounded 16 others.
Although the names of the victims have not been officially released, several family members have come forward to identify their loved ones.
Sgt. First Class Danny Ferguson, a native of Mulberry, Fla., who had just returned from Afghanistan, died while trying to keep the shooter out of the room, Kristen Haley, also a soldier, tells WTSP-TV.
"He held that door shut because it wouldn't lock," Haley, who was nearby when the shooting broke out, tells 10 News, the Tampa TV station. "It seems the doors would be bullet proof, but apparently they're not, If he wasn't the one standing there holding those doors closed, that shooter would have been able to get through and shoot everyone else."
Army officials say a "verbal altercation" may have preceded the shooting spree, but there is no indication that Lopez, who allegedly opened fire and killed three people and wounded 16, was targeting specific individuals.
There is "strong evidence," however, that the Lopez "had a medical history that indicated an unstable psychiatric or psychological condition," Lt. Gen. Mark Milley, head of the Army's III Corps at Fort Hood, said Thursday.
Lopez shot and killed himself after being confronted by a military police officer.
Sgt.Timothy Owens, 37, of Illinois, was also killed in the attack, according to this mother, the Associated Press reports. Mary Muntean, of Effingham, Ill., said she was notified of her son's death by his wife, Billie Owens.
One of the injured soldiers was identified by his wife as Sgt. Jonathan Westbrook, of McComb, Miss., the AP reported. Renee Powell Westbrook said that her husband was recovering from wounds to the chest and neck.
Also injured was as Maj. Patrick Miller, 32, an Iraq War veteran from Allegany, N.Y., who was shot in the abdomen, WGRZ-TV reports.
The third victim was Carlos Lazaney, 38, of Aguadilla, Puerto Rico, NBC News reports, quoting the city's mayor. Mayor Carlos Mendez Martinez said that he had spoken to the victim's aunt.
"They are an excellent family, really good people," he said, according to NBC. "And what's so sad is that he was 38 years old and had joined the military since he was 18. He was going to retire at the end of the year. It is so sad."
The victims have not been officially identified, but were all military personnel.
Milley said the shooter walked into a building on the post Wednesday afternoon and opened fire, got into a car, fired again and then went to another building. He continue shooting until he was met by the female MP. After initially raising his hands, he suddenly pulled out his pistol, put it to his head and killed himself.
Milley did not elaborate on a possible motive for the shooting, but said the "verbal altercation" involved another soldier or soldiers.
"There is a strong possibility that that immediately preceded the shooting,"Milley said. Lopez purchased the .45-caliber Smith & Wesson handgun used in the shootings at a local gun store March 1.
Last month, according to Fox News Latino, Lopez -- purportedly using the name "Ivan Slipknot" on Faecbook, posted comments in Spanish in which he said the "devil had taken him and that he was "full of hatred."
The post, dated March 1, referred to angry over a belief that he had been robbed.
"I have just lost my inner peace, full of hatred, I think this time the devil will take me," Spc. Iván López posted on his Facebook page.
"I was robbed last night and I am sure it was 2 "flacos" (guys). Green light and finger ready. As easy as that."
While the reasons behind the attack remain a mystery, Army officials said that Lopez was being evaluated for post-traumatic stress disorder, but had seen no combat while deployed in Iraq three years ago.
"His records show no wounds, no involvement — direct involvement — in combat," said Army Secretary John McHugh, the U.S. Army's top civilian official. "As Gen. Milley said, no record of Purple Heart or any injury that might lead us to further investigate a battle-related TBI (traumatic brain injury) or such."
Milley said Lopez had "self-diagnosed" a traumatic brain injury. "He was not wounded in action."
On Thursday, McHugh said the suspected shooter had two deployments, including the one in Iraq. Lopez, a native of Puerto Rico who has been married twice and has four children, enlisted as an infantryman and later switched his specialty to truck driver.
Lopez, who was on a variety of prescribed drugs including Ambien, had not yet been diagnosed for post-traumatic stress disorder. But he was also undergoing treatment for depression, anxiety, sleep disturbance and a variety of other issues, McHugh said.
"He was seen just last month by a psychiatrist," McHugh said. "He was fully examined. And as of this morning, we had no indication on the record of that examination that there was any sign of likely violence, either to himself or to others. No suicidal ideation."
Last year, Army psychiatrist Nidal Hasan was convicted and sentenced to death in the Nov. 5, 2009, attack at Fort Hood on his fellow soldiers as they waited inside a crowded building on the base. That shooting spree left 13 dead and more than 30 wounded, in the deadliest attack on a domestic military installation in U.S. history. Hasan was convicted and awaits execution at a federal prison.
The Bureau of Alcohol, Tobacco, Firearms and Explosives on Wednesday night traced the gun used in Wednesday's attack to a local gun shop, said a federal law enforcement official not authorized to comment publicly. The official confirmed that the gun had been purchased at Guns Galore, the same shop that sold a weapon to Hasan.
Pentagon regulations require troops who live off base to register weapons if they intend to bring them onto the installations, Warren said. Those weapons cannot be concealed and base security personnel conduct random checks to ensure compliance, he said.
"We try to do everything we can to encourage soldiers to register their personal weapons, even when they live off post," McHugh said. "We are not legally able to compel them to register weapons when they reside off post."
Soldiers who live on posts in base housing may also keep registered firearms. Soldiers in barracks must keep them in a locked arms room, Warren said.
Contributing: Jim Michaels, Tom Vanden Brook, Ray Locker, Liz Szabo, Donna Leinwand Leger; Army Times