You can't possibly be serious, right? So what is the point of police patrol? Adjusting police presence in different areas? Community initiatives? Prevention is definitively a key component of modern policing at least in every city and country I have lived in.
If that isn't the case in SF I'd say then that they have obviously failed on all levels at enforcing the law. Not to mention, punishment is definitely not the job of law enforcement.
Police departments have fought legal battles specifically to avoid having any duty to protect civilians or to prevent a crime in progress if they so choose.[0] I do agree with you that they (not just in SF, but across America broadly) have in fact obviously failed on all levels, though.
You don't see a link between a police force which actively rejects duty to protect and a police force that doesn't value prevention? It certainly seems to me that a police force which refuses to prevent crimes that are being carried out literally in front of them is one which places low value on prevention.
That isn’t what the law has determined though. The law has only determined that police can’t be sued or imprisoned for failing to assist. It can be my job to pick up trash, but that doesn’t make it my legal obligation even under threat to my own life.
What level of police ubiquity are you proposing, such that it would have prevented two people from two other cities from driving to SF in the middle of the night and starting a fatal altercation inside a car?
Yes and no. Law enforcement's job is in its name. It is to enforce. It is to be the visible arm of otherwise ephemeral law that we agreed upon as society through, hopefully, some sort of consensus. And yes, their presence also serves that purpose, but they are not there to punish ( although I am sure we are all tempted to tip scales at times ). That job is typically the domain of another public institution.
