This is one of our editors' picks from our ongoing roundup of Investigations Elsewhere.

In 2006, investigators with the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives pulled a rare move: They recommended that the agency yank the license of a Milwaukee gun shop. According to an investigation by the Milwaukee Journal Sentinel, the store has sold the bulk of "crime guns" recovered by Milwaukee police in the past decade, including those used to shoot six police officers in two years. And in 2005, it earned the distinction of selling the most crime guns in the country (537 of them).

The store's license wasn't ultimately revoked; instead, the store's co-owner gave it up voluntarily. But if you're in the market for a gun, you can still drive to the same address on South 43rd Street to buy one. Displaying that American knack for reinvention, what was once "Badger Outdoors" became "Badger Guns." And the new owner, the son of one of the previous owners, procured a new license. One of the previous co-owners is retired but still controls the corporation that owns the building; the other co-owner is still an employee.

As the Journal Sentinel puts it, "The moves not only halted the revocation process but also erased violations found by federal regulators over 17 years at Badger Outdoors." The ATF has found more violations at the new store.

Both co-owners of the original store say that they knew nothing about the recommendation to revoke their license; the new owner declined to comment to the paper.

Meanwhile, this seemingly local issue has broader ramifications -- and roots. According to the paper, "a tiny percentage of gun dealers sell a majority of crime guns" -- but the law limits the ATF's ability to crack down:

Federal regulators said they don't track how often gun stores remain open after a license recommended for revocation is relinquished and a new license is issued. They added the law limits their ability to stop it.

When it comes to regulating other licenses, such as alcohol wholesalers, regulators can delve deeply into whether there are secret owners, according to officials at ATF, which used to oversee those licenses. The agency doesn't have that same power when it comes to gun dealer licenses. ...

To revoke a gun selling license, the law requires the ATF to prove that the dealer committed "willful" violations -- a higher standard of proof than for other federal licenses, according to the ATF.

Congress has also shrouded the ATF's investigations in secrecy, sharply limiting what information the agency can release about them.