As a civilian worker I've ridden along with cops in SF. A few decades ago on a first ride through a ghetto they advised me to slouch down in case someone took a pot shot at them from the surrounding low income housing areas. There was a bit of fear in them. A neighbor cop behind my house got murdered in the ghetto by a gunman maybe a decade ago. That ghetto has since improved from the hellhole it used to be. But yes, every city has it's bad area where you watch your back.
THANK YOU for your feedback.
You are correct: hellholes are improving because of the never-ending INCREASED property values in California.
Oakland always did have a VERY posh part of town as well.