Firearm Injury Interventions

Concealed Weapons Laws

Background

One important issue related to firearms is whether allowing individuals to carry concealed handguns increases the risk of injury and death; or conversely, whether restrictions on the right to carry handguns has a net effect on reducing violence related injuries and deaths. As of 1997, at least 30 states have laws allowing authorities to issue concealed weapons permits, compared to only 9 states in 1986. These generally fall into two categories of laws: (1) "may issue" laws, under which legal authorities grant licenses only to citizens who can establish a compelling need for them; and, (2) "shall issue" laws, under which authorities must provide a license to any applicant who meets specified criteria.

This, like many other issues related to firearms, is hotly debated and there have been a number of studies on the impact of legislation related to the right to carry concealed weapons. This literature is reviewed below.


Review of concealed weapons law interventions:

Author

Lott and Mustard, 1997

Study design and target population

Cross sectional time series, at the county level in the United States 1977-92.

Intervention

Right to carry concealed handguns.

Outcomes

Murder, rapes, aggravated assaults, and robberies.

Results

The determined that when RTC laws went into effect, there was a 7.65% decrease in homicide, 5% decrease in rape and 7% decrease in aggravated assault, without a substantial increase in unintentional handgun deaths.

Note that crime rate did not decline until 4 years after RTC laws implemented.

Study quality and conclusions

Claim that permitting concealed weapons is an economical way to reduce crime. Used 2 stage least squares regression (2SLS) to adjust for confounding. Controversial analysis. Webster claims analysis is incorrect because authors failed to control for the cyclical nature of crime rates, made inappropriate assumptions in their statistical models and oversimplified characterization of RTC laws. Reanalysis by Black and Nagin yield results which contradict findings presented here.


Author

Black and Nagin, 1997

Study design and target population

Re-analysis of Lott and Mustard data

Intervention

Right to carry concealed handguns.

Outcomes

Murder, rapes, aggravated assaults, and robberies.

Results

No association between shall-issue laws and violent crime rates.

Study quality and conclusions

They found that crime rates in these states were higher than national trends prior to passage of the laws.


Author

McDowall et al., 1995

Study design and target population

Interrupted time series study design. 3 states in the United States-Florida, Mississippi and Oregon

Intervention

Change from "May issue" to "Shall issue" laws making it easier to obtain a concealed weapon permit, effective 1987 in Florida, and 1990 in Mississippi and Oregon

Outcomes

Homicide rates in Florida (Miami, Jacksonville, Tampa), Mississippi (Jackson) and 3 counties in Oregon(Multnomah, Clackamas, Washington)

Results

Gun homicides increased by an average of 26%; an average increase of 4.5 homicides per 100,000

Conclusions unchanged after adjusting for other gun laws, controlling for variations in national homicide rates and population change.

Effect varied by study area; firearm homicides significantly increased in 3 areas, one area had insignificant decrease. 5 replications, and 2 don’t fit the pattern.

Study quality and conclusions

They conclude that shall issue laws raise levels of firearm murders.

Strengths: used NCHS death certificate data, and time series analyses to evaluate substantial time periods, adjusting for confounders such as age, poverty , historical and population changes, and national homicide trends.

Limitations: evaluated only urban populations, residual confounding may be present.

Summary of concealed weapons law interventions

The studies on concealed weapons laws are not consistent. Lott and Mustard22

  found that the laws actually decrease the risk of violence related death. A re-analysis of their data, however, by others, found that there was in fact no relationship between these laws and risk of violent death, although these authors did not find an increased risk of death. McDowall and colleagues10  found that a change from may issue to shall issue laws was accompanied by an increase in gun homicides.

Recommendations on concealed weapons law interventions

Recommendations for future research