"...at the federal level, gun control advocates have quickly zeroed in on the “high-capacity” ammunition magazine used by the suspect, Jared L. Loughner. Gun magazines that hold more than 10 rounds were banned under the federal assault weapons ban until the statute expired at the end of 2004. Today, just six states and the District of Columbia limit the sale of such magazines. Mr. Loughner was carrying two extended magazines that held 31 rounds each, as well as two "regular" magazines that were not high-capacity, when he opened fire with a semiautomatic pistol on a crowd outside a Tucson supermarket on Saturday, said Deputy Erin Gibson, a spokeswoman for the Pima County Sheriff's office. She added that deputies later recovered 31 shell casings. It was only when he stopped to reload that bystanders were able to tackle him. “The reason he was able to be tackled was he had to pause to reload,” said Dennis Henigan, vice president of the Brady Center to Prevent Gun Violence, a group that works to change gun laws and the gun industry. “The problem is, he didn’t have to pause to reload until he’d already expended 30 rounds.”"