California Code, Revenue and Taxation Code - RTC § 5084

(a) No cancellation shall be made of all or any portion of any unpaid taxes or any penalties or costs levied for prior tax years that constitute a lien at the time of acquisition of exempt property.

(b) Such unpaid taxes, penalties, and costs shall be paid through escrow at the close of escrow or from the award in eminent domain, or if unpaid for any reason, shall be transferred to the unsecured roll pursuant to Section 5090 and are collectible from either the person from whom the property was acquired or the public entity that acquired the property.