On CNN’s "State of the Union with Candy Crowley," Republican Sen. Mike Lee of Utah perpetuated a falsehood about gun ownership and lower murder rates.
Lee: And to the contrary, I think there is abundant research suggesting that in cities where more people own guns, the crime rate, especially the murder rate actually goes down.
That’s not true. A causal relationship between prevalence of gun ownership and crime hasn’t been established by researchers. We looked into this subject in 2008 and found that the statistical relationship is the opposite of what Lee said for murder, a crime that often involves a gun — some studies comparing urban areas to urban areas have found that there are more murders and more murders with guns in areas with more guns. Social scientists have been quick to say this does not indicate a cause and effect. It’s not known if a higher prevalence of guns leads to more violence; it could be that a higher level of violence leads to more guns.
A major study on this issue in 2004 by the National Research Council of the National Academies concluded that research reports "do not credibly demonstrate a causal relationship between the ownership of firearms and the causes or prevention of criminal violence or suicide."