A man opened fire inside a church in a small South Texas community on Sunday, killing 26 people and wounding about 20 others in what the governor called the deadliest mass shooting in the state's history.
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Officials did not identify the attacker during a news conference Sunday night, but two other officials - one a US official and one in law enforcement - who were briefed on the investigation identified him as Devin Kelley.
The US official said Kelley lived in a San Antonio suburb and does not appear to be linked to organised terrorist groups. The official said 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.
At the news conference, Freeman Martin, the regional director of the Texas Department of Public Safety, said the attacker was dressed all in black, wearing tactical gear and a ballistic vest, when he arrived at a gas station across from the First Baptist Church at around 11.20am local time.
He crossed the street and started firing a Ruger AR rifle at the church, and continued after entering the building. As he left, he was confronted by an armed resident who chased him. A short time later, the suspect was found dead in his vehicle at the county line, Mr Martin said. The exact circumstances of his death are unclear. There were several weapons inside the vehicle.
Mr Martin said investigators were not ready to discuss a possible motive for the attack. He said the dead ranged in age from five to 72 years old. Twenty-three were found dead in the church, two were found outside and one died after being taken to a hospital.
Federal law enforcement swarmed the small community 30 miles south-east of San Antonio after the attack to offer assistance, including ATF investigators and members of the FBI's evidence collection team.
Among those killed was the 14-year-old daughter of the church's pastor, Frank Pomeroy, and his wife, Sherri. Sherri Pomeroy wrote in a text message to the AP that she and her husband were out of town in two different states when the attack occurred.
"We lost our 14 year old daughter today and many friends," she wrote. "Neither of us have made it back into town yet to personally see the devastation. I am at the charlotte airport trying to get home as soon as i can."
The wounded were taken to hospitals. Video on KSAT television showed first responders taking a stretcher from the church to a waiting AirLife helicopter. Eight victims were taken by medical helicopter to the Brooke Army Medical Center, the military hospital said.
Megan Posey, a spokeswoman for Connally Memorial Medical Centre, which is in Floresville and about 10 miles from the church, said "multiple" victims were being treated for gunshot wounds.
Alena Berlanga, a Floresville resident who was monitoring the chaos on a police scanner and in Facebook community groups, said everyone knows everyone else in the sparsely populated county. Sutherland Springs has only a few hundred residents.
"This is horrific for our tiny little tight-knit town," said Alena Berlanga. "Everybody's going to be affected and everybody knows someone who's affected," she said.
President Donald Trump tweeted from Japan, where is his on an Asian trip, that he was monitoring the situation. Texas Governor Greg Abbott called the shooting an "evil act."