The man who opened fire on a small church congregation in Sutherland Springs Texas has been identified as Devin Kelley, 26, of New Braunfels, Texas.

Kelley, who at one point served in the United States Air Force, started firing from outside the First Baptist Church of Sutherland Springs around 11 a.m. CT. He then entered the church and continued firing, killing at least 26 people and wounding 10 more, according to officials.

Kelley was dressed in black, wearing a ballistic vest and tactical gear. He was armed with a Ruger assault-type rifle.

He fled the scene in a vehicle was found fatally shot a short time later in Guadalupe County. Authorities said they did not yet know whether Kelley died from a self-inflicted wound or was shot by a local resident who engaged him in gunfire.

A U.S. official said Kelley lived in a suburb of San Antonio and that he doesn't appear to be linked to organized terrorist groups. The official says investigators are looking at social media posts Kelley may have made in the days before Sunday's attack, including one that appeared to show an AR-15 semiautomatic weapon.

The Pentagon said Devin Kelley was an airman in the Air Force "at one point." Air Force spokeswoman Ann Stefanek told USA TODAY that Kelley served in Logistics Readiness at Holloman Air Force Base in southern New Mexico from 2010 until his discharge.

Stefanek said Kelley was court-martialed in 2012 and discharged two years later. He was court-martialed on one count of assault on his spouse and another count of assault on their child. He received a bad conduct discharge, 12 months' confinement and a reduction in rank.

The exact circumstances of his death are still under investigation.