by Kim Krisberg

Amidst discussions of new gun control measures, a study finds that adding new settings where people can bring concealed weapons could increase the risk of some crimes.

The study authors note that while that risk is pretty small, it's still a risk and one that policymakers should take into consideration. Published in the January issue of the American Journal of Public Health, the study examined 2001–2009 data from the Texas Department of Public Safety on criminal convictions associated with holders and nonholders of concealed handgun licenses (CHL). It found that concealed handgun license holders were much less likely than those without a license to be convicted of a crime. Also, most non-license holder convictions involved a higher-prevalence crime, such as burglary or robbery, while convictions among license holders were more likely to involve a lower-prevalence crime, such as a sexual offense or an offense involving a death. Study authors Charles Phillips, Obioma Nwaiwu, Darcy McMaughan, Rachel Edwards and Szu-hsuan Lin write:

The public heath impact of firearms on American society is a contentious issue. With the growth in CHL legislation, the legal carrying of concealed handguns has become an element in the ongoing academic and policy debates over the relationship between public health and firearms. Thus far, empirical results indicate that CHL legislation lowered crime rates, increased crime rates, or had no significant effect on crime rates. As the National Research Council concluded in 2004, “with the current evidence it is not possible to determine that there is a causal link between the passage of right-to-carry laws and crime rates.

The study notes that concealed weapon advocates often cite data examining general crime rates — rates that find license holders are less likely to commit a crime — to argue that concealed handgun licenses are ending up in "safe hands." This study, however, looks at the data differently: Instead of examining overall crime rates, the authors examine the differences in crime convictions between license holders and non-license holders.

In studying the Texas data, the authors found that the most common criminal convictions among non-license holders were simple assaults, robberies and burglaries, all of which accounted for 70 percent of convictions studied among non-license holders. (For example, robbery and burglary accounted for 22 percent of non-license holder convictions, but only 3 percent of convictions among license holders.) When compared with non-license holders, a higher proportion of license-holder convictions were for sexual offenses, weapons offenses, deadly conduct and offenses involving the intentional killing of a person. (For example, among non-license holders, 7.6 percent of convictions were for sexual offenses, while 17 percent of license-holder convictions were for sexual offenses.)

Overall, Texans without a concealed handgun license committed many more crimes than their licensed counterparts. Study authors wrote that "CHL holders rarely 'break bad.' When they do cross the line into illegality, the types of criminality for which they are convicted differ significantly from the convictions of nonlicensees." Such differences are likely due to the demographic characteristics of concealed handgun license holders and the availability of handguns. In other words, weapons offenses may be more likely among those with a license precisely because they're more likely to have a gun with them.

As policymakers consider expanding the types of places where people can bring concealed weapons, such as in schools or churches, the authors noted that their study results show such a policy change could increase gun-related offenses in previously gun-free zones.

"Holders of a CHL in Texas in 2001 to 2009 were almost universally a law-abiding population, like most individuals who shared their demographic characteristics," the study authors wrote. "However, in those rare instances when they committed crimes...they were more likely to be convicted for serious weapons-related offenses."

According to the study, from 1987 to 2010, the number of states that allow people to carry concealed handguns grew from 10 states to 40 states.

For more on the study, visit www.ajph.org.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for the last decade.