Things like street layout and patterns of street use can make an enormous difference to how safe places feel. And then you get feedback from that - places that feel dangerous get more dangerous, because of the way people use them, and with places that feel safe it's the other way round.

Generalisations about a "place" as big as the USA are never going to have much force. Much more intriguing to work out why it is that within countries and regions some places throw up more violence than others, especially comparing places which superficially seem pretty similar.