drive legislation to ban civilian possesion of assault weapons such as but not limited to large capacity firearms

The shooting of 20 children and 6 adults was a tragic event in Newton, Connecticut. However, this and many similar tragedies could have been avoided. Armed with semi-automatic weapons it was easy for the killer to kill all these innocent people. I understand that people have the right to bear arms, but how is it possible to have army caliber weapons in the hands of civilians? The bottom line is that if all civilians were barred from having this kind of firearm nobody would able to do this kind of mass killing. The cons unanimously outweigh the pros.