Every time the US suffers another mass shooting, gun rights activists make an argument that goes something like this: if a good guy with a gun had been there, this terrible tragedy could have been prevented.

That argument has been dismissed by gun control groups as an unrealistic suggestion that diverts attention away from the need to strengthen laws restricting firearm access, but a shooting that occurred over the weekend has now supercharged the “good guy with a gun” defense.

Two people were shot dead on Sunday morning during a church service in White Settlement, Texas, before the attacker was shot and killed by two members of the church’s security team. Groups such as the National Rifle Association are now pointing to the duo’s heroism to suggest that states hoping to tackle gun violence should pass laws expanding firearm access.

“A gunman open-fired at a White Settlement, Texas church, and within three seconds, a good guy with a gun stopped him. This was possible due to critical changes to Texas law in 2017,” the NRA tweeted shortly after the shooting.

Following the 2017 shooting at a church in Sutherland Springs, which left 26 people dead, the Texas attorney general, Ken Paxton, issued an opinion stating that “unless a church provides effective oral or written notice prohibiting the carrying of handguns on its property, a license holder may carry a handgun on to the premises of church property as the law allows”.

Paxton’s opinion was codified into Texas law earlier this year, clearing the way for church security teams like the one at White Settlement. After news of the shooting broke, Republican lawmakers and conservative commentators jumped to echo the NRA’s rationale, emphasizing the need to allow “good guys with guns” to carry weapons into houses of worship.

“Two of the parishioners who are volunteers on the security force drew their weapons and took out the killer immediately, saving untold number of lives,” said the Texas lieutenant governor, Dan Patrick. After the former Democratic presidential candidate Beto O’Rourke called for stricter gun laws in response to the killings, Fox News contributor Katie Pavlich replied: “The shooter was stopped within three seconds, preventing further carnage, by a law-abiding citizen carrying a firearm. He is a hero. You are a moron.”

The Texas governor, Greg Abbott, praised the church members for “swiftly ending the attack”.

But the gun-control group Newtown Action, which was founded after the 2012 shooting at Sandy Hook elementary school, pointed out that the congregant who shot the gunman was reportedly a former FBI agent.

Such instances of defensive firearm use are also rare in the larger landscape of America’s gun violence. According to the not-for-profit Gun Violence Archive, only 1,532 gun violence deaths in the US this year have been the result of defensive use, representing about 4% of the total number of such deaths.

That total figure – 39,150 gun violence deaths in 2019 – now includes the two innocent congregants who were shot in the span of a few seconds on Sunday, despite the presence of a “good guy with a gun”.