[Oakland] How to identify protected tenants?

[Calvin Kwan]

So I'm escrow for a place in Oakland and the seller is having trouble getting estoppels from the existing tenants.  Both seller and tenants have lost their leases, and the tenants have been dragging their feet on signing the estoppels.  

My main concern about the tenants is not knowing if any of them are protected.  The sellers are both in hospice care, so we're dealing mostly with the listing agent.  

Do you guys have any advice on how to find out status of existing tenants before purchase?  There's one main tenant paying the rent, but there are 6 people living in the unit.  My goal is to move into the vacant unit of the duplex, decontrol the property, then raise the rent to market after a year.

Thanks.