I think that's a bad idea. In fact, I propose that we not only continue the death penalty, but that we expand it's current usage. I think that instead of trying to ban weapons, we use the death penalty as a discouragement to those who would shoot up classrooms, movie theaters, churches, etc..
When a person who does such a thing, or even if we find a person who we can prove is planning such an action, we should take him and his evidence to a judge who will summarily try and convict him and sentence him to death. That execution should take place on the same day as his conviction. Walk the guy out of the jail and up a gallows right there on the courthouse grounds, put his neck in a noose and drop him like a sack of potatoes. Let him hang there overnight and his relatives can claim the body the next day and take it for burial. That will be the end of him, but will also serve as notice to others who might be planning to kill innocent people.
My point is simple, and it goes to the discussion of banning firearms. You will never be able to confiscate the hundreds of millions of firearms that are in the hands of both criminals and law-abiding citizens. But you can show everyone what awaits those who use those firearms to commit mass murder. If you want to stop the killings, you have to make the punishment so 'over the top' and so distasteful that no one in their right mind would dare commit a crime that demands that punishment.
