Flags lowered at U.S. Capitol
2:29 p.m.: In Washington, the flags at the U.S. Capitol were lowered to half-staff in remembrance of the victims in Sunday's attack.
House Speaker Paul Ryan posted a picture of the Capitol on Twitter on Monday.
1:39 p.m.: Deputies visited gunman's house in 2014
Authorities in Texas say law enforcement went to Devin Patrick Kelley's home three years ago to investigate a domestic violence complaint involving him and his then-girlfriend.
Paul Anthony, a spokesman for the Comal County district attorney's office, told The Associated Press that sheriff's deputies were called just after 10 p.m. on Feb. 1, 2014, to the New Braunfels home of Kelley and his family.
Citing a sheriff's office report, Anthony says a friend of Kelley's girlfriend told authorities she received a text message from the girlfriend that indicated "her boyfriend was abusing her." When sheriff's deputies arrived at the home, they were told by people in the house that there was no problem.
No arrests were made. Kelley married Danielle Shields two months later.
Kelley was discharged from the Air Force the same year after being punished for assaulting his spouse and child.
1:27 p.m.: Gunman's neighbors surprised he attacked church
Sutherland Springs, Texas, is a small town of only a few hundred people where everybody seems to know everybody else, and the community was still trying to process Sunday's attack.
Devin Patrick Kelley came from a nearby town, and his neighbors were surprised to learn he's the man accused of carrying out the shooting, CBS News correspondent Jeff Glor reports.
"It's pretty shocking to find out your neighbor just did something like that," Mark Moravitz said.
Moravitz's wife Terry Moravitz said she was stunned.
"What's going through my mind right now is I'm stunned," she said. "I would have never have thought this from my neighbor nor his son."
12:42 p.m.: Authorities tie 3 weapons to gunman
Authorities have tied three firearms to Devin Patrick Kelley following Sunday's attack.
Special Agent Fred Milanowski of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives told reporters during a news conference Monday that Kelley purchased all three weapons.
A Ruger 556 rifle was found at the First Baptist Church. Texas Department of Public Safety regional director Freeman Martin earlier said that Kelley dropped the rifle outside after being confronted by an armed area resident.
Milanowski said that two handguns, a Glock 9 mm and a Ruger .22-caliber pistol, were recovered from a vehicle where Kelley was found dead after a high-speed pursuit by a truck driver who was flagged down by the armed resident.
Martin said that Kelley didn't have a license to carry firearms.
12:11 p.m.: Church attack "wasn't over religious beliefs," authorities say
Texas authorities believe Devin Patrick Kelley's attack during Sunday morning services wasn't over religious beliefs.
Texas Department of Public Safety regional director Freeman Martin told reporters during a press conference that Kelley had sent threatening text messages to his mother-in-law, who Martin said attended services at First Baptist Church.
Earlier Monday, Wilson County Sheriff Joe Tackitt told CBS News that Kelley's ex-wife and former in-laws sometimes attended services at the church but were not there during Sunday's attack. Kelley had been married twice.
"We wanted to get that out there that this was not racially motivated, it wasn't over religious beliefs," Martin said. "There was a domestic situation going on within the family-in-laws."
11:37 a.m.: Gunman called dad during high-speed chase
Devin Patrick Kelley called his father during a high-speed chase after Sunday's attack, Texas authorities announced Monday morning.
Texas Department of Public Safety regional director Freeman Martin told reporters during a press conference that Kelley called his father on his cellphone while he was being chased by two men in a truck.
Kelley was wounded and told his father that he didn't think he was going to make it, Martin said. Kelley subsequently shot himself and died.
Before the chase, Kelley was shot outside the church by an area resident responding to the shooting. Kelley then fled in a vehicle.
The area resident then flagged down a man driving a truck, and the pair pursued Kelley.
10:45 a.m.: Gunman worked as Bible teacher, source says
Devin Patrick Kelley did some work as a Bible teacher, a law enforcement source told CBS News.
CBS News senior investigative producer Pat Milton reports it's not yet known for which church the gunman in Sunday's attack worked.
The law enforcement source said Kelley's page on the social networking site LinkedIn listed his job as a management consultant but doesn't say where he worked. Kelley had a high-school education.
10 a.m.: Calls for armed guards at churches after attack
There are calls in Texas and across the U.S. to post armed guards at churches to prevent acts of violence like Sunday's deadly attack. But some critics say that strategy could backfire, CBS News correspondent Mark Strassmann reports.
Bishop Darnell Dixon believes the best way to protect his church in Raleigh, North Carolina, is with armed defenders.
"If I call people together, it is incumbent upon me to make sure that they are safe," Dixon said.
Dixon is voicing his concerns following Sunday's massacre -- and a long list of religious sanctuaries hit by gun violence.
In an effort to make it easier for places of worship to provide volunteer security services, Texas passed a law in June waiving state requirements on training, licensing and background checks.
9:20 a.m.: Gunman's ex-wife, in-laws occasionally attended targeted church
Devin Patrick Kelley's ex-wife and former in-laws sometimes attended services at the church he attacked Sunday, the sheriff in Sutherland Springs confirmed to CBS News.
Kelley's former family members were not in the First Baptist Church during the Sunday morning attack, Wilson County Sheriff Joe Tackitt said. The former in-laws drove to Sutherland Springs Sunday afternoon.
Kelley was married twice. He married his first wife in 2011 when he was 20 and married another woman in 2014.
8:40 a.m.: Sheriff says "strong people" in Sutherland Springs
The sheriff in Sutherland Springs told CBS News that Sunday's church attack will be traumatic for many residents in the Texas community, but he believes that they'll come together.
Wilson County Sheriff Joe Tackitt told CBS News correspondent Jeff Glor that he grew up in the community.
"This is a close-knit community," Tackitt said on "CBS This Morning." "I mean, everybody here in the community knows everyone, you know, and they help each other, and this is going to be traumatic for a lot of people, but they're going to come together. They're strong people."
8:16 a.m.: Authorities believe gunman killed himself
Authorities believe Devin Patrick Kelley died of a self-inflicted gunshot wound, the sheriff in Sutherland Springs told CBS News.
Wilson County Sheriff Joe Tackitt told CBS News correspondent Jeff Glor that Kelley shot himself after he tried to get away from the First Baptist Church in Sutherland Springs.
Kelley was being chased by two men in a truck after attacking the church during Sunday morning services.
Tackitt said Kelley "wrecked out" during the chase, and that's when Tackitt believes Kelley shot himself.