For all its visual ugliness, there isn't that much violent crime in San Francisco, compared to New York under Dinkins. It's mostly quality of life crime - bums, grafitti, trash, poorly maintained streets and sidewalks, no apparent police presence (I don't know where they all came from when we had the anti-war protests - I didn't even know we had that many!) and an overall malaise that comes from Democrats and Progressives (Communists) holding every single political office and every important appointed post in city government.
City Supervisor Gavin Newsom is running for Mayor. He is a liberal Democrat, which makes him a conservative by the standards of San Francisco politics, and he is determined to end the problem of bums owning the streets. I doubt he can do it by himself even if he does get elected, but things might improve a little bit.
By the way, I only work in San Francisco. I would never live there.