Effects of restrictive licensing of handguns on homicide and suicide in the District of Columbia.

BACKGROUND

Whether restricting access to handguns will reduce firearm-related homicides and suicides is currently a matter of intense debate. In 1976 the District of Columbia adopted a law that banned the purchase, sale, transfer, or possession of handguns by civilians. We evaluated the effect of implementing this law on the frequency of homicides and suicides.

METHODS

Homicides and suicides committed from 1968 through 1987 were classified according to place of occurrence (within the District of Columbia or in adjacent metropolitan areas where the law did not apply), cause (homicide or suicide), mechanism of death (firearms or other means), and time of occurrence (before or after the implementation of the law). The number of suicides and homicides was calculated for each month during the study period, and differences between the mean monthly totals before and after the law went into effect were estimated.

RESULTS

In Washington, D.C., the adoption of the gun-licensing law coincided with an abrupt decline in homicides by firearms (a reduction of 3.3 per month, or 25 percent) and suicides by firearms (reduction, 0.6 per month, or 23 percent). No similar reductions were observed in the number of homicides or suicides committed by other means, nor were there similar reductions in the adjacent metropolitan areas in Maryland and Virginia. There were also no increases in homicides or suicides by other methods, as would be expected if equally lethal means were substituted for handguns.

CONCLUSIONS

Restrictive licensing of handguns was associated with a prompt decline in homicides and suicides by firearms in the District of Columbia. No such decline was observed for homicides or suicides in which guns were not used, and no decline was seen in adjacent metropolitan areas where restrictive licensing did not apply. Our data suggest that restrictions on access to guns in the District of Columbia prevented an average of 47 deaths each year after the law was implemented.