The bipartisan national group with the apt name Mayors Against Illegal Guns has won a major victory. For some states, including Indiana, there's more to lament than celebrate.

The coalition made up of more than 350 municipal chief executives -- 10 from Indiana, none from Central Indiana -- managed to persuade Congress to ease access to once-closely guarded "trace data," the federal records of traffic in firearms used in crimes.

And what did those records show?

That 10 states, Indiana included, were the source of 57 percent of the guns used in crimes outside those states.

That those states tended to have the weakest laws governing the sale and tracking of guns.

That those weak laws correlate with higher rates of in-state murder and shootings of police officers.

In the current furor over the fate of the Second Amendment at the hands of a Democratic president and Congress, the mayors' report supplies a wake-up call about the need for balance. The right to bear arms must by all means be protected; but the freedom to deal in deadly weapons must stop where public endangerment begins.

Indiana has no history of bucking the gun lobby at the state political level, and guns were a non-issue again this year in legislative and gubernatorial races. The new report was sent to all 50 governors; a spokeswoman for Gov. Mitch Daniels said he had not read it and had no comment on it. Nor does he have any firearms-related proposals to present to the legislature in this coming session, the aide said.

Without question, the governor and lawmakers have plenty on their plate already, what with property taxes, local government reform, health care and education crying out for action while the state budget faces a massive shortfall and the economy continues heading south. Yet there has to be a way, if there's a will, to address Indiana's role in a scourge that takes thousands of lives every year across the United States.

If lawmakers were inclined to take on this life-and-death matter, they might consider five measures the mayors cited as keys to keeping guns away from criminals:

Background checks at gun shows.

Purchase permits.

Reporting of lost or stolen guns.

Allowance for local control.

State inspections of gun shops.

Indiana has none of these requirements. Nor does it limit the number of guns that can be purchased at one time, thus encouraging so-called straw purchasers who resell weapons on the street. This gives Indiana the dubious distinction, according to authorities, of being a supply station for gang members from states such as Illinois that do demand accountability for where these lethal commodities end up.

Have gun-control laws quelled violence in Chicago, or in the cities headed by the coalition's co-chairs, Boston (Tom Merino) and New York (Michael Bloomberg)? Of course not. But the mayors and their police chiefs declare from experience that hardheaded restrictions have helped -- and that the free flow of weapons from states such as Indiana makes their jobs tougher. The new report, a product of tenacious lobbying for information that never should have been secret, reinforces their case. It should be received in every state with thanks and deadly seriousness.