Former Arizona Rep. Gabrielle Giffords was struck in the head by the first bullet from a gunman's 33-round magazine in 2011, but the 13th bullet killed a 9-year-old girl nearby, according to an amicus brief filed by the Giffords Law Center to Prevent Gun Violence. The center said the gunman, who was tackled when he tried to reload, might not have killed the child had he had less firepower. Nineteen people were shot outside an Arizona supermarket that day, six fatally. Giffords survived.