I guess it all depends on the size of property that you're trying to secure, but
MURS Radio would be a good option for small/medium rural properties.
There is still the problem of dealing with the perps once they're detected. Again, in this legal environment in California, that confrontation is fraught with financial peril for a property owner while the "professionals" (police) are too busy dealing with methamphetimized gangland. It's probably cheaper just to let the crooks get away.
We're really in a world of hurt out here with this legislature.