Beside having a Gun Control owners should also be more calm and ensure that their mood won't affect on thwir decision when using it.
There is no way to ensure this. A person who seems calm and peaceful today may be the one who kills a few dozen tomorrow in a terrorist attack. Mood depends on a lot of things.
So the only viable method is to remove guns from the criminals, and the mentally deranged, and allow gun ownership for everyone else.
Be careful that you don't let Government declare that all of its citizens are mentally deranged if they want to have guns.
