The killer wore a bulletproof vest and a mask with a white skull on it.
By contrast, his adversary, Stephen Willeford, was barefoot.
Willeford was at home Sunday in Sutherland Springs when his daughter first heard the shooting next door at the First Baptist Church, and he went over to see what was happening. He had friends inside.
What happened next was a scenario nearly unheard of in mass shootings, but one often suggested by those in favor of a well-armed citizenry: An armed bystander got in a shootout with a mass killer and chased him out of town.
Two of Willeford's shots apparently hit Kelley, one in the leg and one in the torso. The gunman dropped his weapon and fled in an SUV.
Willeford had been brave enough — and skilled enough. But he had not quite been fast enough. Back at the church, Kelley had killed 26 people and wounded 20 others, including many children, in the fifth-deadliest shooting in modern American history.
On Monday, as more details about the shooting became clear, the gunman and the good Samaritan seemed to increasingly represent the two poles of the nation's political debate over gun control and gun ownership.
On one end of the political spectrum, Willeford embodied the NRA's axiom that "the only thing that stops a bad guy with a gun is a good guy with a gun" — the argument that the best defense against mass shootings is a better-armed and better-trained civilian populace, ready to defend itself, anywhere, at a moment's notice.
"This is going to happen again," Texas Atty. Gen. Ken Paxton, a Republican, told Fox News. "All I can say is in Texas at least we have the opportunity to have concealed carry," including in churches, and he suggested "at least arming some of the parishioners so they can respond to something like this."
On the opposite side of the spectrum, Kelley seemed to represent liberal criticisms of the nation's easy access to weapons. He had a record of domestic violence but was allowed to buy four guns between 2014 and 2017, including the high-velocity semiautomatic rifle he used to kill his victims.
Kelley, who served in the Air Force but was kicked out for violent behavior, seems to have fallen between the cracks of the nation's background-check system because of a clerical error.
"It is simply too easy for dangerous people to buy guns, and strengthening our background-check system is a critical step in stopping them," Kris Brown, co-president of the Brady Campaign gun control group, said in a statement.
"All Americans should be asking our leaders, how is it that a man who was court-martialed for domestic abuse and later discharged from the military was able to purchase these guns?" Brown said.
In 2012, Kelley was court-martialed for cracking his young stepson's skull and assaulting his wife. Court records released by the Air Force reveal that he was also accused of pointing a gun at his wife, but those charges were dropped. He was convicted and sentenced to a year of confinement at the Naval Consolidated Brig Miramar in San Diego before receiving a bad-conduct discharge in 2014.
"This guy should not have been allowed to buy a gun," said Rachel VanLandingham, a retired judge advocate for the Air Force who is now a professor at Southwestern Law School, citing federal law.
VanLandingham said that normally when an investigation is opened for a serious offense on an Air Force base, an entry is made into an FBI database.
After the results of a court-martial are published, she said, investigators are supposed to enter the disposition into the database — which, in this case, would have barred Kelley from buying a gun.
"I don't know where the breakdown happened," she said. "That's the million-dollar question."
In a statement, the Air Force confirmed that Kelley's conviction was not entered into the FBI's National Crime Information Center database as it should have been.
The branch's top officials ordered an internal review to be led by the inspectors general of the Air Force and the Defense Department that will also examine whether other cases have been misreported.
That oversight meant it was ultimately up to Willeford to be the first one to face down a dangerous gunman.
After Willeford struck Kelley, “He got into his vehicle and he fired another couple rounds through his side window,” Willeford told a Texas television station. That’s when Willeford flagged down a pickup driver, Johnnie Langendorff, 27, and the pair started chasing the gunman.
They sped after Kelley, reaching 95 mph on the two-lane county roads surrounding Sutherland Springs before Kelley drove his SUV off the road.
“We got within just a few feet of him and then he just drove off the road,” Langendorff said in an interview.
The two men waited on the road, Willeford’s gun aimed at Kelley’s vehicle. The SUV and its driver didn’t move.
Five minutes later, dozens of law enforcement officials descended on the scene. Kelley was dead. Before he crashed, he had used his cellphone “to notify his father that he had been shot and that he didn’t think he was going to make it,” said Freeman Martin, regional director of the Texas Department of Public Safety. “Subsequently, he shot himself.”
While most of the shocked residents of the closely-knit, deeply religious and largely pro-gun community were in no mood to discuss the politics of gun rights after Sunday’s events, they seemed to agree on one thing: Langendorff and Willeford were heroes, and they represented the best of Sutherland Springs.
Langendorff, who on Monday was wearing a cross on a chain around his neck, a pearl snap shirt and a cowboy hat, was matter-of-fact about how it had all gone down.
"I just did what I had to do," he said. "I don't feel like a hero. I just did what most people around here would do."