Having lived in SF and having traveled there frequently since, I am going to say that SF's PD is a joke. It's almost unbelievable. I was assaulted twice in SF (the last time about 10 years ago - didn't go again for at least 5 years after that). I knew it was pointless to call the police, because I had witnessed people being assaulted and beaten (on the streets, in a motel parking lot, outside a restaurant - 3 different times, really scary, employees at the restaurant came to the person's aid, but the motel employees locked up their office and hid).
I was told to use their online form to report these events! I still follow San Francisco on reddit and it is still the same. Their clearance rates on homicides, last I checked, was very low. They claim they don't have the staff. And it's probably true - the entire area has so much "petty crime," but that breeds other crimes and everyone should know that.
I just checked and now their clearance rate is unusually high. I am skeptical.
I have worked with lots of different LE agencies (never with SF, though) and I am not anti-LE at all. I just think the SFPD is useless. Since their clearance data became public, they suddenly have a 100% clearance rate for last year's homicides. I don't trust that number, as I believe they're using the "exceptional means" category to get that rate.
Anyway, if we look at the clearance rate on other crimes...it's not good:
Clearance Rates Dashboard | San Francisco Police Department
I believe SFPD puts all its effort into clearing crimes, and very little into "at risk" missing persons. They only clear about 35-40% of assaults (and those are usually very serious, none of the assaults I witnessed nor my own assaults were serious - probably just bruising). There's this "tradition" among wannabe gang members that they have to assault some innocent person, usually a woman, while their homies look on, to get one foot on the first rung of the gang ladder. I believe that's what happened to me the last time, and the previous time, I believe the person was mentally ill. The first time, I was knocked down, the second time I was able to stay on my feet (and thank god my DH didn't see it happen, as he would have gone ballistic - which is part of why they do it, to start fights that they will finish with group violence).
If you look at the assault clearance rate, above, you'll see what I mean. Or even sex trafficking - as you can see, it's not a cheerful picture.