When you say "criminals, predators and the immoral", are you only referring to Americans?
Homicide by gun:
U.S.  31 per million
Germany, Austria, Netherlands:  2 per million
England, Poland:  1 per million
Japan: 0.1 per million

Those 6 countries mentioned are very different historically, ethnically and culturally; but they all have much stricter gun control laws than the U.S.