Hello. My name is Marc. I'm a licensed attorney and I will be happy to answer your questions. I can imagine how vexing this situation must be for you! And the police response is mind boggling.
California Penal Code 602 PC prohibits the crime known as criminal trespass. Put very simply, you may commit the California crime of trespassing when you enter . . . or remain on . . . someone else's property without permission or a right to do so.1
California trespass law sets out literally dozens of situations in which the offense of trespass may take place...some that are common, and some that are highly unusual or even a bit bizarre. The most common acts that are prohibited by California trespassing laws include:
- entering someone else's property with the intent to damage that property,
- entering someone else's property with the intent to interfere with or obstruct the business activities that are conducted there,9
- entering and "occupying" another person's property without permission, and
- refusing to leave private property after you've been asked to do so.
Now, in your case, the last bullet listed above is applicable. Based on the facts you have conveyed, you are the lawful occupant of the house (note: even if you were merely a tenant, rather than the owner, this would still apply). Some guy is in your house. The guy does not have permission - either contractual, implied or otherwise - to be in your house. And finally, the guy refuses to leave. Thus, this situation contains all the required elements of criminal trespass under CA law.
As to why the police turned you away, I can only guess that they might have misunderstood this situation to be essentially a sort of landlord-tenant issue, which, as a civil matter, would not be within their jurisdiction. But it is not, and you need to explain that to them. Cite for them the following section of the Penal Code:
California's criminal trespassing law. ("(o) Refusing or failing to leave land, real property, or structures belonging to or lawfully occupied by another and not open to the general public, upon being requested to leave by (1) a peace officer at the request of the owner, the owner's agent, or the person in lawful possession, and upon being informed by the peace officer that he or she is acting at the request of the owner, the owner's agent, or the person in lawful possession, or (2) the owner, the owner's agent, or the person in lawful possession.")
Ask the police how it is that this guy is not committing criminal trespass. I cannot imagine how they could determine otherwise. The result, once they realize there's a person committing this crime in your house, they have authority to arrest him and charge him with misdemeanor criminal trespass. Furthermore, if he has made any threats to you, he could be charged with aggravated criminal trespass, a felony.
I hope this helps! I hope I've provided you with useful information that helps you better understand your issues and options. If so, please be sure to rate my answer, since that is the only way I can receive credit.
I wish you luck and a speedy resolution to this problem!