The suspect whohas been identified as 26-year-old Devin Patrick Kelley, law enforcement sources tell CBS News.
Authorities on Sunday only identified the suspect as a young white male. They said he was dressed in all black and tactical gear when he opened fire at the First Baptist Church in Sutherland Springs. After a car chase with police, the suspect was shot and declared dead. It's unclear if the suspect shot himself or if he was killed by police.
The shooting left at least 26 people dead and 20 others injured in what Texas Gov. Greg Abbott described as the worst mass shooting in his state's history.
Kelley is a former U.S. Air Force member who served from 2010 to 2014. He was dishonorably discharged and court-martialed in May 2014, CBS News has learned.
He has a residence in New Braunfels, Texas, which is about a 35-mile drive from where the attack took place in Sutherland Springs.
Air Force spokesperson Ann Stefanek told The Associated Press that records show Kelley served in Logistics Readiness at Holloman Air Force Base in New Mexico from 2010 until his discharge. The circumstances under which he left the service were not immediately available.
The Pentagon told the AP that Kelley was an airman "at one point," but did not provide additional details.
Officials say the suspect lived in a San Antonio suburb and doesn't appear to be linked to any organized terrorist groups. CBS News has learned Kelley has a wife named Danielle Lee Shields.
Investigators will look at his social media posts made in the days prior to Sunday's attack -- including one that appeared to display an AR-15 semiautomatic weapon. Kelley's date of birth is listed as Feb. 21, 1991.
No motive has been declared as the investigation continues.
Sutherland Springs is about 35 miles southeast of San Antonio.
This story is developing. Check back for updates.