Cal. Government Code § 12955.8

For purposes of this article, in connection with unlawful practices: (a) Proof of an intentional violation of this article includes, but is not limited to, an act or failure to act that is otherwise covered by this part, that demonstrates an intent to discriminate in any manner in violation of this part. A person intends to discriminate if race, color, religion, sex, gender, gender identity, gender expression, sexual orientation, marital status, national origin, ancestry, familial status, source of income, disability, veteran or military status, or genetic information is a motivating factor in committing a discriminatory housing practice even though other factors may have also motivated the practice. An intent to discriminate may be established by direct or circumstantial evidence. (b) Proof of a violation causing a discriminatory effect is shown if an act or failure to act that is otherwise covered by this part, and that has the effect, regardless of intent, of unlawfully discriminating on the basis of race, color, religion, sex, gender, gender identity, gender expression, sexual orientation, marital status, national origin, ancestry, familial status, source of income, disability, veteran or military status, or genetic information. A business establishment whose action or inaction has an unintended discriminatory effect shall not be considered to have committed an unlawful housing practice in violation of this part if the business establishment can establish that the action or inaction is necessary to the operation of the business and effectively carries out the significant business need it is alleged to serve. In cases that do not involve a business establishment, the person whose action or inaction has an unintended discriminatory effect shall not be considered to have committed an unlawful housing practice in violation of this part if the person can establish that the action or inaction is necessary to achieve an important purpose sufficiently compelling to override the discriminatory effect and effectively carries out the purpose it is alleged to serve. (1) Any determination of a violation pursuant to this subdivision shall consider whether or not there are feasible alternatives that would equally well or better accomplish the purpose advanced with a less discriminatory effect. (2) For purposes of this subdivision, the term “business establishment” shall have the same meaning as in Section 51 of the Civil Code.