Under U.S. law, a person who has been convicted of a misdemeanor crime of domestic violence is prohibited from possessing firearms, but it is unclear if there are exceptions in this case that may have allowed the purchase to go forward.
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The alleged gunman has been identified as Texas native Devin Kelley from New Braunfels, federal and state law enforcement sources confirmed.
At least 27 people were killed and at least 27 injured after the shooting at First Baptist Church in Sutherland Springs.
MORE: Officials: 26 dead, dozens injured in Texas church shooting
The 26-year-old shooter was found dead in his car after fleeing the scene, though investigators are still working to determine whether or not it was the result of a self-inflicted wound.
Wilson County Sheriff Joe Tackitt told a local newspaper that a man walked into a Baptist church in Sutherland Springs, Texas, and opened fire, leaving multiple people dead.
Here is more on what we know about Kelley:
-Kelley, who served in the Air Force from 2010 until 2014, was court-martialed in 2012 on charges of assault on his spouse and on their child. He received a bad conduct discharge, confinement for twelve months and a reduction of his military status.
-Kelley purchased the Ruger model AR-556 rifle used in the shooting at a San Antonio sporting goods store in April 2016, according to a law enforcement official.
-He was dressed in all black with tactical-type gear and was wearing a ballistic vest.
-He was at a Valero gas station before he drove across the street to the church, exited his vehicle and opened fire, according to officials from the Texas Department of Public Safety.
-He moved to the right side of the church and continued to fire before he entered the church and shot people inside.
-As he exited the church, a local resident grabbed his rifle and "engaged" the suspect. The suspect dropped what was described as a Ruger AR assault-type rifle and fled from the church.
-The local citizen pursued the suspect and when law enforcement responded, the suspect crashed and was found deceased in his vehicle.
-It was not immediately clear whether he died from a self-inflicted gunshot wound or if he was shot by the local resident.
-Multiple weapons were found in the vehicle, and the vehicle was being processed by special operations group bomb techs.
-Authorities are searching his social media accounts and said that on Facebook in recent days, he showed off what appeared to be an AR-15-style gun.
-An ATF source said that agents are searching the alleged shooter's home for explosives.
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