The U.S. Air Force is investigating why the Texas church gunman's domestic violence conviction that got him jailed and thrown out of the service was not properly entered into the FBI database.
If it had been, Devin Kelley would have been stopped from legally buying an assault rifle and may not have murdered 26 people Sunday in the tiny town of Sutherland Springs.
WATCH: Who was the Texas shooter?
Kelley was an airman from 2010 until 2014. Air Force spokeswoman Ann Stefanek says he was court-martialed in 2012 for beating his wife and stepson. He received a bad conduct discharge, reduction in rank and military prison time.For reasons that are unclear, the Holloman Air Force Base Office of Special Investigations did not properly follow Pentagon rules and provide the information to the FBI for its National Criminal Information Center database.
The Air Force has ordered a review of the Kelley case and says it will ensure all such cases are reported.
The FBI agent in charge of the investigation in Texas, Christopher Combs, says there was nothing in its system that prohibited Kelley from getting the weapons when a background check was carried out.
Kelley passed a federal background check, but the state of Texas denied him a permit to carry a gun.
President Donald Trump, speaking in South Korea Tuesday, said "extreme vetting" on gun purchases would not have made any difference in preventing the massacre.
"And you might not have had that very brave person who happened to have a rifle in his truck go out and shoot him and hit him and neutralize him," Trump said, referencing an armed bystander who confronted Kelly outside the church.
At a Monday night news conference, the FBI's Combs refused to say Kelley's name, saying he does not want to glorify him. Combs would only call him "the gunman."
Combs said "horrific" is too weak a word to describe the scene inside the First Baptist church. Twenty-six people were killed; 20 were wounded.
Texas public safety official Freeman Martin said as of Monday evening, 10 of the victims are in the hospital in critical condition and four in serious condition.
The youngest fatality was 18 months old. A pregnant woman was also killed.
Martin, who also refused to use Kelley's name, said the gunman came to the church with a purpose and a mission.
A domestic dispute with his in-laws appeared to have been behind the killings. Kelley is said to have sent "threatening texts" to his mother-in-law, who did not attend Sunday's service.
"This was not racially motivated ... wasn't over religious beliefs. There was a domestic situation going on within the family and in-laws," Martin said.
Kelley was dressed in black and wore a skull mask. He opened fire outside the church with a Ruger 556 assault rifle and kept shooting when he went inside the building. He was confronted by a church neighbor who was armed with his own rifle. Kelley fled the scene with the neighbor in pursuit, soon joined by police.
The chase ended when Kelley crashed his car and shot himself in the head. He died at the scene. Martin said he had two other bullet wounds from the neighbor.
Kelley telephoned his father as he sped from the church, telling him that he had been shot and does not expect to survive.
Kelley fired a total of 450 rounds of ammunition at the church.
Governor, president respond
Texas Governor Greg Abbott told CBS News, "It's clear this is a person who had violent tendencies, who had challenges. Someone who was a powder keg waiting to go off."
The deadly mayhem in Texas came a month after the worst mass shooting in U.S. history, when a man named Stephen Paddock opened fire on a country music show in Las Vegas, killing 58 people and wounding about 500. Paddock shot from his 32nd floor hotel room and killed himself as police zeroed in. Investigators are looking for a motive.
WATCH: Trump on Texas Church Shooting
U.S. President Donald Trump, traveling in Asia on a five-nation trip, said the Texas shooting "isn't a guns situation" but "a mental health problem at the highest level. It's a very, very sad event." He said the shooter was "a very deranged individual."
Trump ordered U.S. flags on federal buildings to be flown at half-staff through Thursday.
WATCH: Texas shooting reactions
"We cannot put into words, the pain and grief we all feel and we cannot begin to imagine the suffering of those who lost the ones they so dearly loved. Our hearts are broken," the president said.Marie Ann Montgomery, the church's Sunday school director, said people in the congregation knew Kelley. While none of the victims has been publicly identified, First Baptist Church Pastor Frank Pomeroy told U.S. news networks that his 14-year-old daughter, Annabelle Renee Pomeroy, is among the deceased. Pomeroy was in Oklahoma at the time of the shooting but returned to Sutherland Springs.
He said all of the people killed Sunday were close friends. Pomeroy also said he wants the world to know his daughter "was one very beautiful, special child."
VOA's Carla Babb, Ken Bredemeier and Fern Robinson contributed to this report.