(Based on The State Bar of California Standing Committee on Professional Responsibility and Conduct Formal Opinion No. 2016-195.)

One of the most important duties of an attorney is to preserve the secrets of his client, and “[n]o rule in the ethics of the legal profession is better established nor more rigorously enforced than this one.” (Wutchumna Water Co. v. Bailey (1932) 216 Cal. 564, 572.)

Preserving the confidentiality of client information contributes to the trust that is the hallmark of the client-lawyer relationship. (In re Jordan (1974) 12 Cal.3d 575, 580.) Attorney-client privilege is necessary to “safeguard the confidential relationship between clients and their attorneys so as to promote full and open discussion of the facts and tactics surrounding individual legal matters.” (Mitchell v. Super. Ct. (1984) 37 Cal.3d 591, 599.)

Legal Standard

The duty of an attorney is “[t]o maintain inviolate the confidence, and at every peril to himself or herself to preserve the secrets, of his or her client.” (Bus. & Prof. Code, § 6068(e)(1).) The attorney-client privilege is a statutorily created evidentiary rule that protects from disclosure a “confidential communication” between a lawyer and his or her client. (Evid. Code, § 954; Solin v. O’Melveny & Myers (2001) 89 Cal.App.4th 451, 456-57.)

“Although exercise of the privilege may occasionally result in the suppression of relevant evidence, the Legislature of this state has determined that these concerns are outweighed by the importance of preserving confidentiality in the attorney-client relationship.” (Costco v. Super. Ct. (2009) 47 Cal.4th 725, 732.)

The party claiming the privilege has “the burden of establishing the preliminary facts necessary to support its exercise, i.e., a communication made in the course of an attorney-client relationship. Once that party establishes facts necessary to support a prima facie claim of privilege, the communication is presumed to have been made in confidence and the opponent of the claim of privilege has the burden of proof to establish the communication was not confidential or that the privilege does not for other reasons apply.” (Id. at p. 733.)

For purposes of the attorney-client privilege, “confidential communication” is defined as “information transmitted between a client and his or her lawyer in the course of that relationship and in confidence.” (Evid. Code, § 952; In re Jordan (1972) 7 Cal.3d 930, 939-40.) The principle of client-lawyer confidentiality applies to information relating to the representation, whatever its source, and encompasses matters communicated in confidence by the client, and therefore protected by the attorney-client privilege, matters protected by the work product doctrine, and matters protected under the ethical standards of confidentiality, all as established in law, rule and policy. (In the Matter of Johnson (Rev. Dept. 2000) 4 Cal. State Bar Ct. Rptr. 179, 189.) In other words, information protected by the ethical duty of confidentiality is broader than what is protected as attorney-client privilege under the Evidence Code. (Id. at p. 189.)

Former Clients

“[A]n attorney is forbidden to do either of two things after severing his relationship with a former client. He may not do anything which will injuriously affect his former client in any matter in which he formerly represented him nor may he at any time use against his former client knowledge or information acquired by virtue of the previous relationship.” (Wutchumna, supra, 216 Cal. at pp. 573-74; Oasis West Realty, LLC v. Goldman (2011) 51 Cal.4th 811, 822-23.)

When an attorney’s representation of a current client may conflict with the interests of a former client, the duty to maintain client confidences is jeopardized. (M’Guinness v. Johnson (2015) 243 Cal.App.4th 602, 613.) Where an attorney’s representation of a former client is substantially related to the attorney’s representation of a current client, a presumption arises that the attorney has obtained confidential information from the former client. (Fiduciary Trust Internat. of California v. Super. Ct. (2013) 218 Cal.App.4th 465, 480.)

“To rebut the presumption, the challenged attorney has the burden of showing that the practical effect of formal screening has been achieved. The showing must satisfy the trial court that the employee has not had and will not have any involvement with the litigation, or any communication with attorneys or coemployees concerning the litigation, that would support a reasonable inference that the information has been used or disclosed. If the challenged attorney fails to make this showing, then the court may disqualify the attorney and law firm.” (In re Complex Asbestos Litigation (1991) 232 Cal.App.3d 572, 596.)

Disqualification

“A former client may seek to disqualify a former attorney from representing an adverse party by showing the former attorney actually possesses confidential information adverse to the former client.” (Costello v. Buckley (2016) 245 Cal.App.4th 748, 754.) “There is no strict requirement of precise relationship between the factual and legal issues of the two cases.” (Id.)

“[T]he purpose of a disqualification must be prophylactic; an attorney may not be disqualified purely as a punitive or disciplinary measure.” (Neal v. Health Net, Inc. (2002) 100 Cal.App.4th 831, 844.)

“A trial court’s authority to disqualify an attorney derives from the power inherent in every court to control in furtherance of justice, the conduct of its ministerial officers, and of all other persons in any manner connected with a judicial proceeding before it, in every matter pertaining thereto.” (In re Charlisse C. (2008) 45 Cal.4th 145, 159.)