The President has already urged Congress when it comes back to work to take up initiatives -- legislation to ban assault weapons, to ban high-capacity magazines, and to improve our background checks system because it does have loopholes.

WHITEHOUSE: Press Briefing by Press Secretary Jay Carney,

You have to work back from there -- and this is a little bit of an imprecise science -- but you have to work back from there to allow for what it would take to write and pass legislation that would take care of this issue.

WHITEHOUSE: Press Briefing