-- Panicked parishioners inside the First Baptist Church in Sutherland Springs, Texas, had little cover and nowhere to run when a gunman approached and started firing an assault rifle, Wilson County Sheriff Joe Tackitt Jr. said.
Tackitt said investigators believe the suspect, 26-year-old Devin Kelley, began firing as he approached the church, then shot his way to the front and back out again.
Kelley is suspected of killing 26 people and injuring at least 20 others in one of the deadliest mass shootings in modern U.S. history.
"I don't think they could have escaped," Tackitt said of the churchgoers, according to The Associated Press.
Witnesses reported seeing a man dressed in combat gear shooting relentlessly into the small church.
"I went to the window to look, and I see an armed man dressed in riot gear — I guess that's what you call it — SWAT gear," Fred Curnow, who lives nearby, told ABC affiliate KSAT. "Fully masked, fully armored. He was just shooting the church from the outside."
Curnow said the suspect "kept unloading clip after clip," estimating the shooter went through at least six clips in and around the church.
"I'm right in the doorway, and I looked around, and there's just [shell] casings everywhere," Curnow said. "I looked to the side, and I saw a couple of small children. They were — they were not moving."
Kelley, who served in the Air Force from 2010 to 2014, was court-martialed in 2012 and discharged for bad conduct in 2014. He was found dead in his car after fleeing the scene, though investigators are still working to determine whether it was the result of a self-inflicted wound.
Neighbors said they heard rapid gunfire coming from around Kelley's home in the days leading up to the shooting rampage.
"It's really loud. At first I thought someone was blasting," Ryan Albers, 16, told The Associated Press. "It had to be coming from somewhere pretty close. It was definitely not just a shotgun or someone hunting. It was someone using automatic weapon fire."
Another neighbor, Mark Moravitz, told KSAT that he didn't notice anything unusual about Kelley but also mentioned hearing gunfire.
"Shocking. [You] never think your neighbor is capable of something like that," he said. "I mean, the only thing unusual across the street is we hear a lot of gunfire, a lot of times at night. We hear gunfire a lot, but we're out in the country."
The Associated Press contributed to this report.