Legal Question in Real Estate Law in California

I would try visiting the Los Angeles County Registrar-Recorder's office in Norwalk and looking up the land records to see if there is anything.recorded there.

The Health & Safety Code contains a major section regulating cemeteries. The regulations vary somewhat depending upon whether they are public, private (corporate), religious, military, etc., but there is a good chance this particular one is required by law to maintain records of (a) who is buried there and when, and (b) ownership of all plots. See, for example, Health & Safety Code section 8331 which reads, "A record shall be kept of the ownership of all plots in the cemetery which have been conveyed by the cemetery authority and of all transfers of plots in the cemetery. Transfer of any plot, heretofore or hereafter made, or any right of interment, shall be complete and effective when recorded on the books of the cemetery authority."

Between checking the cemetery's records and the recorder's records as Mr. Stone suggests, you should be able to come up with enough information to establish ownership.