More to the point, in the former mill cities - I am very familiar with Lawrence, having lived nearby it nearly all my life - I would estimate it's a quality of life issue more than anything else. Crime is just endemic; there's really no other way to put it, and no way to make it sound better than it is. The crime leads to a civic complacency, which in turn feeds back into the crime. It's a municipal death spiral that started a half century ago, and it's being perpetuated largely in part by politicians who turn a blind eye to it because it serves their purposes.
Here (caution, language)