A timely reminder: "Keeping lawful citizens unarmed won't reduce number of criminals"
The only sure way to reduce violent crime is to reduce the number of violent criminals.
Studies show that criminals are less risk-averse than the population at large. In fact, it turns out that people who commit crimes actually seek out risk.
My one complaint with the piece is that it uses numbers that I say in my book are unreliable. The purely cross-sectional comparison is made because that is what most people do, but it is very misleading and exaggerates the benefits from right-to-carry laws.