In almost every case where
guns are used to kill other people, either the people who do the shooting were using
illegally - obtained
guns anyway, and so better
gun control wouldn't have stopped them from
getting the
guns in the first place, OR the people shooting the
guns would have qualified to own
guns by any proposed
gun control standard.
Of course if
guns were made impossible to
get legally, you would still be able to
get them somehow
illegally... but, that means they could & probably would demand a much higher price due to lack of competition, as well as risk factor for seller & buyer if caught, due to much steeper sentencing that should go with such dealings.