The explosion of new laws allowing citizens to carry firearms concealed is a large factor in the crime drop over the last 10 years.
I'm old enough to remember the horror and gnashing of teeth when Concealed Carry was proposed in Texas.
The media assured us there would be gun battles in the streets every 15 minutes over contested parking spaces if filthy sinner humans were allowed to carry self-defense weapons.
The exact opposite happened.
Homicides rates:
United States 4.8[9]
Germany 0.8
Much more to come...
Compared to say Canada the homicide rate are much lower as well.
https://en.wikipedia.org/wiki/List_of_countries_by_firearm-related_death_rate 10.3 as compared Canada 2.38. Mexico has 11.17 and Australia 1.06
I wonder why Japan has such unbelievable low rates...
But it offers no real explanation other than culture.