Uvalde report and 'NRA Math': Why nearly 400 'good guys with guns' couldn’t stop one bad guy

A report on the Uvalde school shooting released over the weekend left some questioning the accuracy of the National Rifle Association’s long-standing mathematical equation: “The only thing that stops a bad guy with a gun is a good guy with a gun.”

The Texas House committee report on the shooting that left 19 children and two teachers dead found that nearly 400 law enforcement officers were on the scene but failed to halt the slaughter. The Texas Tribune referred to the size of the police presence at Robb Elementary School as “a force larger than the garrison that defended the Alamo.”

And yet, this collection of good guys with guns failed to stop one bad guy with a gun before he murdered 21 people.

So what went wrong? Why did the NRA's tried-and-true equation fail? As an expert on what’s known as “NRA Math,” I think I can explain.