ONE REGULAR REFRAIN of gun-rights extremists is that tough gun laws do little or nothing to curb gun crimes, because criminals don't obey them.

That thinking is as simplistic (and long-lived) as the old bumper sticker that proclaimed, "When guns are outlawed, only outlaws will have guns."

Actually, a recent study by the Boston University School of Public Health confirmed what everyone should know by now: Tough gun laws work. That study concluded that waiting periods before a gun purchase, the requirement of a permit to buy a gun, forbidding gun purchases by people with violent misdemeanors on their record, and seizing guns from those convicted of such misdemeanors could result in a cumulative decrease in gun crime of almost 14 percent.


Still, outmoded thinking and false claims by gun rights advocates persist. One regular conservative retort to calls for tougher gun laws is a five-word refrain: How's that working in Chicago?

Actually, when it comes to gun crime in Chicago, the focus should be less on the Windy City's gun laws than on those of nearby states. Almost 60 percent of guns used in crimes in Chicago come from places with weak guns laws, Indiana, Wisconsin, and Mississippi prominent among them.

The BU study found the same thing nationally. It concluded that, for guns used in crimes, "the general pattern of gun flow was from states with weak gun laws to those with strong gun laws: from Southeastern states with weak gun laws up the coast to Maryland, New York, and Massachusetts; from Midwestern states with weak gun laws to Illinois; and from Western states with weak gun laws to California."

New data from the Boston Police Department highlights the same dynamic. As the Globe's Danny McDonald recently reported, almost half of the guns – 333 — used in crimes in Boston last year came from out of state, compared with 138 from Massachusetts. (The remainder couldn't be traced.)


No surprise there: Massachusetts has strict gun laws, including the requirement for a background check and permit before anyone can buy a gun in state.

Still, nearby states like New Hampshire, Maine, and Vermont have weak guns laws. In any of those states, one can buy a gun from a private seller at a gun show (or elsewhere) without a background check. New Hampshire and Maine rank prominently as sources of guns used for crimes in Massachusetts.

Rural states sometimes justify their weak gun laws by saying that since they don't have a high gun crime rate, they don't need stricter laws. But the more data that become available, the more it becomes apparent that their weak laws are contributing to gun crimes elsewhere.

And that's just another reason that sensible gun laws should be a priority everywhere.