This may help, too:

https://old.reddit.com/r/ManchesterNH/comments/grypup/what_is_considered_the_ghetto_in_manchester/

Manchester is kid gloves for people used to real cities, but there's some areas ("the tree streets") that generally have the majority of the crime.

There's nowhere I feel uncomfortable walking in Manchester, really outside of places that would be sketchy anywhere alone at night.