Any rifle or pistol that fires semi-automatic or automatic is not for sporting use. It is a weapon that can be used against people. Weapons for personal defense were appropriate when we were fighting in Colonial times, but now we have a standing army and community police departments.
Weapons can be used against children and law enforcement officers as we have recently seen. It is time to make possession of these weapons illegal and have the weapons confiscated if they are not turned in during a "buy back" program.
Institute a mandatory five year prison term, with no parole, for anyone using one in the commission of a crime.
Close all loopholes so none can be imported into the United States.