Sen. Dianne Feinstein, D-Calif., said Sunday she will introduce legislation next year to ban new assault weapons, as well as big clips, drums and strips of more than 10 bullets.
Police say the gunman, Adam Lanza, was carrying an arsenal of ammunition big enough to kill just about every student in the school if given enough time. He massacred 20 students and six teachers and administrators before shooting himself in the head just as he heard police drawing near, authorities said.
A Connecticut official said the gunman's mother was found dead in her pajamas in bed, shot four times in the head with a.22-caliber rifle. The killer then went to the school with guns he took from his mother and began blasting his way through the building.
"There is no blame to be laid on us but there is a great burden and a great challenge that we emerge whole," First Select Woman Patricia Llodra said. "It is a defining moment for our town, but it does not define us."
AP White House Correspondent Ben Feller contributed to this report.