"To stop a bad guy with a gun, it takes a good guy with a gun."
That's what Wayne Lapierre, head of the National Rifle Association (NRA), said in the wake of the Valentine's Day shooting at a Florida high school.
- Maryland high school shooter dies after critically injuring two students
- Texts show mother-daughter panic as shooter roams US school
It's a popular theory among gun enthusiasts, but there's little evidence to suggest that more firearms make people safer.
However an officer's heroism in the face of yet another school shooting is being heralded as an example of the theory.
Austin Wyatt Rollins, 17, shot two students at Great Mills High School in Maryland on Tuesday morning. Before he could harm anyone else, he was killed when the school's lone resource officer burst onto the scene.
Blaine Gaskill intervened in the attack after less than a minute, shooting at the gunman at the same moment Rollins fired a round. It's unknown whether the shooter killed himself or if he died after being shot by Mr Gaskill.
A 16-year-old female student sustained life-threatening injuries and is in critical condition. She is believed to be a former girlfriend of Rollins.
A 14-year-old male student who was also shot is in a stable condition.
Deputy Gaskill has been praised for his bravery and quick thinking by the Governor of Maryland.
"This is a tough guy who apparently closed in very quickly and took the right kind of action," Larry Hogan said.
"And while I think it's still tragic, he may have saved other people's lives."
He's also earned the admiration of another powerful American presence: the NRA.
Spokesperson Dana Loesch claimed the "mainstream media" weren't giving the shooting enough coverage.
"This [Great Mills High School] armed school resource officer, you're not hearing anyone in #MSM talk about it because it disrupts their narrative," she said in a broadcast by an NRA TV channel.
Deputy Gaskill's actions are markedly different from what the resource deputy of Stoneman Douglas High School did during the massacre on February 14. Scot Peterson took up a position outside the school after gunman Nikolas Cruz began shooting, but never entered the building.
Dr James Scott Smith, superintendent of St Mary's County public schools, said if the Great Mills shooting proved anything, it's that no guns are better than a good guy with a gun.
"It looks as though the SRO [school resource officer] did exactly what the SRO is trained to do, and yet we still have a tragic loss of life."