Legal Question in Criminal Law in California

Armed police are the ones charged with 'defense' of civilians who can not defend themselves, homeless or not. You could file a crime report with whatever credible evidence you have, and see what they say. You can seek housing and shelter out of dangerous areas.

In terms of defending yourself with the most effective tool for doing so, LA is quite 'anti-' gun in the hands of law abiding citizens for self defense, and yet not so much interested in arresting, prosecuting or incarcerating repeat offending violent criminals that victimize those denied the tools for defending themselves. Those who can afford it hire armed security, carry concealed firearms [with or without CCW permits that are essentially unobtainable in LA], and 'harden' their vehicles and walled / gated homes; the rest of us are left on our own.

You have to do what you can to avoid risk, no one else can do it for you. It may surprise you that police are under no legal obligation to 'protect' every or any particular person, nor respond to every call for help, such as from 911. They can not be on guard waiting in every dangerous location.

The answer is to keep criminals off the streets, in prison, and out of decent society. Demand it of your elected so-called 'representatives' that have the power to make necessary charges, that is if they care about actually reducing crime instead of outlawing tools for self defense.

Good luck.