.223-caliber Bushmaster semi-automatic assault rifle similar to one used in the shootings at Sandy Hool Elementary School in Newtown, Connecticut, Dec. 14, 2012
President Clinton approved a federal ban on assault weapons in 1994, but it expired in 2004 under President George W. Bush. Sen. Dianne Feinstein, D-Calif., says she will introduce legislation that would restore the assault weapons ban.
Assault weapons: A primer
USA Today