That has all sorts of knock-on effects: people close to a murder victim lose the sense that the state will do something about their loss, so they take the matter into their own hands; people who commit homicide are a tiny minority but if they're not apprehended, they can keep committing homicides, which makes a broader society feel less safe; people sense that the state, their city, their neighbors, etc don't care about them because if the homicide was of someone in a richer neighborhood, it would be more likely to be solved; etc. Been a while since I read it so I'm forgetting a lot.
I think this goes some way towards explaining why people in neighborhoods where lots of violent crime is committed have such ambivalent feelings about the police - they are at once underpoliced (police don't solve major crimes in their neighborhood) and overpoliced (police bust people for all kinds of small-time stuff, which has devastating long-term consequences).
At the same time as all of the above, it's also true that it's basically never been safer to live in a big American city (ok ok, at least since like the 1960s - before then the picture gets significantly more complicated). So it's safer than ever, but big crimes don't get prosecuted or solved, unless they happen in the "right" neighborhoods. The solution therefore isn't more of the same police; maybe it's more policing but the policing itself needs to change.
Homelessness is a profound and society-wide problem, with no easy answers unless you consider "spend way more money, build way more housing" an easy answer (which I do).
Until we do those things, it should be no surprise that a region with skyrocketing rents has a housing crisis, and that will present itself in myriad unpleasant ways.