Yes, there is the 2nd amendment and I always hear after any school shooting when the debate starts about better gun control that it's their right but as you say, that was made years ago when things were different and now that it's more of an occurrence than it ever was, I do feel that something needs to be done to better gun control because the 2nd amendment just isn't it anymore.
I myself live in the UK and I always remember there was ONE school shooting in Scotland that changed the gun laws forever in the UK. Now we are starting to see guns coming in through the black market and being used in the country and even though our gun laws are still as strict as they always have been since that school shooting. I feel more now needs to be done to stop guns from coming into the country and landing in the wrong hands.