Joe Zamudio says the handgun he was carrying led him to run toward the sound of bullets being fired in Tuscon and help stop Jared Lee Loughner. Zamudio is being touted as a hero who proves the Second Amendment can save lives. But Zamudio almost killed another hero at the scene of Rep. Gabrielle Giffords' shooting--the man who snatched the gun from Loutner.

Slate's William Saletan cautions that we should look a bit closer at Zamudio's story before embracing conceal-and-carry, gun advocates' answer to those worried about shootings. "This is a much more dangerous picture than has generally been reported," Saletan writes. "Zamudio had released his safety and was poised to fire when he saw what he thought was the killer still holding his weapon. Zamudio had a split second to decide whether to shoot. He was sufficiently convinced of the killer's identity to shove the man into a wall. But Zamudio didn't use his gun. That's how close he came to killing an innocent man. He was, as he acknowledges, 'very lucky.'" Concludes Saletan:

That's what happens when you run with a firearm to a scene of bloody havoc. In the chaos and pressure of the moment, you can shoot the wrong person. Or, by drawing your weapon, you can become the wrong person—a hero mistaken for a second gunman by another would-be hero with a gun. Bang, you're dead. Or worse, bang bang bang bang bang: a firefight among several armed, confused, and innocent people in a crowd. ... We're enormously lucky that Zamudio, without formal training, made the right split-second decisions. We can't count on that the next time some nut job starts shooting.