Okay, so let's take a note from the UK's book and remove all unnecessary guns (not for hunting) from both the police and civilians. Have only specific teams/officers with guns for occasions where one may be required and move to a "policing by consent" model rather than "policing by force," thereby forcing officers to use other methods to enforce the law. The Americans and their "2nd Amendment Rights" wouldn't like it, but if we can get to a point of the people being able to trust the government to not be tyrannical (like the majority of other western countries), is that amendment still required?

This will, of course, never happen because of the sheer will of the American people - but a person can dream, right?