Cal. Government Code § 25539.2

When the legislative body of a county finds the public interest and convenience require the sale for less than the market price of residential property acquired by the county, it may pass an ordinance providing for such sale. The ordinance shall set forth the procedure to be followed in completing such sales, including the qualifications required of a purchaser of such property, and shall contain provisions requiring that the purchaser of the property live in the property for a specified length of time and must rehabilitate such property to the extent specified in the ordinance; provided, however, that title to the property shall not be transferred until all the requirements set forth in the ordinance have been satisfied. Upon the transfer of title by the county pursuant to any ordinance adopted under the provisions of this section, compliance with the requirements of the ordinance shall be conclusively presumed in favor of a bona fide purchaser or encumbrancer for value. Persons eligible to purchase such residential property shall be persons and families of low or moderate income, as defined by Section 50093 of the Health and Safety Code. To the greatest extent possible, counties shall utilize such ordinances to assist very low income households, as defined by Section 50105 of the Health and Safety Code, and lower income households, as defined by Section 50079.5 of the Health and Safety Code.