Wyoming is suing the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.
The lawsuit, filed Monday in U.S. District Court, centers on whether its the federal government or the state that has the final authority to restore gun rights to those guilty of misdemeanor domestic violence offenses.
Under federal law, people convicted of any misdemeanor crime of domestic violence used to be prohibited from possessing a firearm. In 1986, that changed: Those convicted could own a gun if their records were expunged.
A new Wyoming law, passed in 2004, set up a process for letting people convicted of misdemeanor offenses -- including, but not specifically, domestic violence acts -- regain their gun rights. The state, however, used a different definition of "expunge," setting off a series of battles with ATF.
In July 2005, ATF said it would notify federally licensed firearms dealers that concealed weapons permits from Wyoming were invalid unless the state changed its law.
Monday's lawsuit is the state's most recent response.
"The BATF's actions are an illegal attempt to force BATF's will upon the Wyoming Attorney General and Wyoming's duly elected legislature," wrote Attorney General Pat Crank and Senior Assistant Attorney General C. Levi Martin.