You can find out if there is a recorded Trustee's Deed Upon Sale from the Riverside County Recorder's Office or from a local title insurance company.
As a tenant, you have rights under both federal and state law. The Protecting Tenants at Foreclosure Act of 2009 (PTFA), part of the Helping Families Save Their Homes Act of 2009 (Public Law 111-22, approved May 20, 2009), requires that tenants residing in foreclosed residential properties be provided notice to vacate at least 90 days in advance of the date by which the immediate successor, generally, the purchaser, seeks to have the tenants vacate the property. Except where the purchaser will occupy the property as the purchaser's primary residence, the terms of any bona fide lease also remain in effect.
In addition, new protections for tenants of foreclosed homes took in California on January 1, 2011.
The information presented here is general in nature and is not intended, nor should be construed, as legal advice. This posting does not create any attorney-client relationship with the author (who is only admitted to practice law in the State of California). For specific advice about your particular situation, consult your own attorney.
Public records. As Mr. Chen says. Realtor may not know. Landlord may not know. Public records don't 'lie'.
This is general legal information, not intended to apply to your specific case. And I may not be licensed to practice in your particular state. Under Federal Law, I am a debt relief agent.