How Common Are Defensive Gun Uses?

You've likely heard the saying: "The only way to stop a bad guy with a gun is a good guy with a gun."

But what is the true number of defensive gun uses?

Here & Now's Robin Young hears from two researchers who study the impact of firearms on society and have gone back and forth on that question: Florida State University criminologist Gary Kleck, and David Hemenway, a professor of public health at Harvard University.