At some level, it becomes reasonable for families and neighborhoods to seek their own retribution rather than rely on the rule of law.
We are far past that point, but any effort at neighborhood self-protection would be ferociously investigated and prosecuted by the authorities.
I live in a now0gentrified neighborhood, but 20 and 30 years ago it was a little sportier. My tongue in cheek suggestion then was that if we wanted a real crackdown on crime, we should lynch a local drug dealer. That would have drawn saturation police coverage, a stakeout in every alley, security cameras everywhere, and roving SWAT teams to protect journalists reporting on the alarming outbreak of vigilante justice. All it would have taken is one hanging of a thug. The resulting police presence would have saved many lives over time.
The authorities in Democrat controlled cities are far more hostile to armed citizens than to criminals.