States with lax firearm laws are more likely to sell guns that are later exported to other states and then used in crimes, a national coalition of mayors charged in a new report.

The top 10 states account for 49 percent of the guns used in out-of-state crimes, according to a report released yesterday by Mayors Against Illegal Guns, a coalition of almost 600 U.S. mayors.

Mississippi and West Virginia, for example, are among the states that do not enable prosecution of gun buyers who falsify purchaser information or of gun dealers who fail to conduct a background check on a buyer.

Mississippi led the nation in so-called crime-gun exports, providing 50.3 out-of-state guns per 100,000 residents. West Virginia was second with 46.8 guns per 100,000, the report found.

In Pennsylvania, which ranks No. 30 in guns exported per capita, more than 1,700 guns used in out-of-state crimes last year were traced back to the state. That's an average of 14.1 guns exported per 100,000 residents, same as the national average.

New Jersey ranked 48th with 2.8 guns per 100,000 residents. Delaware was 23rd with 18.5 guns per 100,000 residents.

Members of the coalition say the findings show the need for nationwide gun legislation to prevent people with easy access to guns from supplying criminals with them out of state.

"I think a report like this has people sit up and take notice at which states are exporting guns and which states are being victimized by this," said Reading Mayor Thomas McMahon, who chairs the coalition in Pennsylvania.

"It makes sense to have some common legislation we can all rely upon instead of letting the weakest states making it toughest on the rest of us."

Mayor Nutter, a member of the coalition, said the report "reiterates what Philadelphians already know - that illegally trafficked guns result in crime and death in our city's streets. Philadelphia and all cities in the United States need strong, common-sense gun laws that keep weapons out of the hands of criminals."

A spokeswoman for the National Rifle Association said the organization was withholding comment until its research department had finished analyzing the report.

The report draws its conclusions from data of guns confiscated at crime scenes provided by the Bureau of Alcohol, Tobacco, Firearms and Explosives.

When the export numbers are not adjusted for population, the report ranks Pennsylvania seventh in the number of exported guns.

Out-of-state guns are also coming into the state. The study found that 1,142 guns from other states were involved in crimes in Pennsylvania last year.