In Michael A. Fletcher's "The Crime Conundrum" [Style, Jan. 16], I didn't read about one factor that seems to have contributed to the decrease in crime: Thirty-one states permit law-abiding citizens to carry concealed firearms for self-protection. Sadly, the District is not among those jurisdictions and has banned possession of handguns since 1976. Half the U.S. population, including 60 percent of handgun owners, live in right-to-carry states.

The fact that right-to-carry is both popular and effective in fighting crime flies in the face of the gun-banners' philosophy. States that have right-to-carry laws have lower violent crime and homicide rates on average compared with the rest of the country, including a 24 percent lower total violent crime rate, a 19 percent lower homicide rate, a 39 percent lower robbery rate and a 19 percent lower aggravated assault rate.

One key to suppressing crime is to raise the cost to criminals: A Department of Justice study found that 40 percent of felons chose not to commit at least some crimes for fear that their victims were armed, and 34 percent admitted being scared off or shot at by armed victims. Concealed carry by law-abiding citizens works and should be expanded, especially in high-crime areas such as the District.

LEE FOULLON

Falls Church