Police Lieutenant Lowell Duckett, President of the Black Police Caucus, and Special Assistant to the Washington D.C. Police Chief had this say about gun control in Washington D.C.:
Gun control has not worked in D.C. The only people who have guns are criminals. We have the strictest gun laws in the nation and one of the highest murder rates. It's quicker to pull your Smith and Wesson than to dial 911 if you're being robbed. [ref]
Most big cities in the U.S. have very strict gun control laws, yet disproportionately high murder rates compared to rural areas with much higher per-capita gun ownership.
If guns really were responsible, regions with less gun control and higher gun ownership would have higher murder rates. They don't.