Well, to talk of Vermont, you get into issues such as, there are relatively few members of minority groups in that state, and no big cities.
I’m sure it’s “politically incorrect” of me to make note of those aspects of Vermont contributing to a lower crime rate, and rate of gun violence in particular. But there are reasons why Vermont doesn’t have the same social and violence problems as places such as urban New Jersey.
I remember when Vermont had NO MURDERS. Way back in 1967 or 1968.