The Tiahrt Amendment is a provision of the U.S. Department of Justice appropriations bill that prohibits the National Tracing Center of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) from releasing information from its firearms trace database to anyone other than a law enforcement agency or prosecutor in connection with a criminal investigation.[1] This precludes gun trace data from being used in academic research of gun use in crime.[1] Additionally, the law blocks any data legally released from being admissible in civil lawsuits against gun sellers or manufacturers.[1] Some groups, including Mayors Against Illegal Guns, believe that having further access to the ATF database would help municipal police departments track down sellers of illegal guns and curb crime. These groups are trying to repeal the Tiahrt Amendment.[2] Numerous police organizations oppose the Tiahrt Amendment, such as the Major Cities Chiefs Association (MCCA) and the International Association of Chiefs of Police (IACP).[citation needed] The Tiahrt Amendment is supported by the National Rifle Association (NRA),[2] and the Fraternal Order of Police.[citation needed] The NRA says that undoing the Tiahrt Amendment would lead to a rash of lawsuits against gun dealers.