Government can no more regulate against violence using guns any more than it can regulate against deaths caused by hurricanes, tornadoes, floods, or earthquakes. The argument would be, "Well, those are acts of God (one of the few times Libs will reference God, by the way)."
Wasn't Lanza's actions an unpreventable act of God as well? He knows in advance when each of us will be called home. Like it or not, we were not made to understand this, and we can never grasp "why?" The best way to help our children, and all of the citizens of this nation, is to encourage prayer, strengthen our faith, and to bring ourselves closer to Him. Violent acts are a part of the evil world, but not of the home He has created for us.