From a November 14, 2012 report of the Congressional Research Service via Federation of American Scientists
Congress has debated the efficacy and constitutionality of federal regulation of firearms and ammunition, with strong advocates arguing for and against greater gun control. In the wake of the July 20, 2012, Aurora, CO, theater mass shooting, in which 12 people were shot to death and 58 wounded (7 of them critically) by a lone gunman, it is likely that there will be calls in the 112th Congress to reconsider a 1994 ban on semiautomatic assault weapons and large capacity ammunition feeding devices that expired in September 2004. There were similar calls to ban such feeding devices (see S. 436/H.R. 1781) following the January 8, 2011, Tucson, AZ, mass shooting, in which 6 people were killed and 14 wounded, including Representative Gabrielle Giffords, who was grievously wounded. These calls could be amplified by the August 5, 2012, Sikh temple shooting in Milwaukee, WI, in which six worshipers were shot to death and three wounded by a lone gunman.