The gunman in Sunday’s Texas church massacre was convicted in a military court for abusing his wife and daughter, and served a year behind bars.

That should have been enough to prevent him from legally buying or possessing firearms under a 1997 federal law, known as "the Lautenberg Amendment," which bars access to guns for anyone convicted of a crime of domestic violence, according to some legal experts.

But federal authorities are still looking to officially confirm whether Devin Patrick Kelley’s 2012 court-martial and 2014 bad conduct discharge from the Air Force were sufficient grounds to bar him from purchasing the three guns recovered from Kelley’s vehicle after his death from a suspected self-inflicted gunshot.

“What I will tell you right now is that in general, if an individual has a dishonorable discharge from the military they would be prohibited from possessing or purchasing firearms and this specific investigation we are early in the investigation, we do not have all the documentation yet,” said Fred Milanowski, a ATF field agent at a news conference Monday.

“Until we can get all the documentation to determine exactly what his discharge and conviction in the military we will not have a determination on if this individual was prohibited from possessing or purchasing firearms,” Milanowski said.

The Air Force said Kelley received a bad conduct discharge, which is not as serious as a dishonorable discharge, after his conviction on two counts of assault and subsequent confinement for 12 months.

Federal law specifies dishonorable discharges as a disqualifying factor, but does not mention bad conduct discharges. Texas authorities revealed that Kelley also passed a background check to be licensed as an unarmed security guard.

“There were no disqualifiers entered into the national crime information center database that would preclude him from receiving a private security license,” said Freeman Martin of the Texas Department of Public Safety.

“Private security background checks including fingerprints and criminal history checks for the Texas crime information center and national crime information center databases were checked, and he was cleared,” Martin said.

Texas Gov. Greg Abbott said at one point Kelley was denied a license to carry a gun in Texas, according to CNN.

"So how was it that he was able to get a gun? By all the facts that we seem to know, he was not supposed to have access to a gun," CNN quoted Abbott as saying. "So how did this happen?"