Ethics Opinon 1989-4


Attorney has been hired by Law Firm to act as an expert witness in case #1, a matter being handled by Law Firm. Later, Attorney represents Client in Case #2, a litigation matter wholly unrelated to case #1. The party who opposes Client in case #2 is represented by Law Firm.


Must Attorney disclose to Client the Attorney's relationship with Law Firm?

Does it make any difference whether case #2 is a litigation or a transactional matter?

Assume Attorney is a member of law firm X. If Client is represented by a lawyer from X, but not by Attorney, must anyone make a disclosure?


No California Rule of Professional Conduct expressly requires that this relationship between attorneys be disclosed to a client. However, the attorney's duty of loyalty to the client requires that the attorney exercise caution, and discloses the relationship if the attorney's own interests might adversely affect representation of a client.


California Rule of Professional Conduct 3-320 on its face, and by its title, is the rule governing relationships between attorneys. It provides as follows:

Rule 3-320. Relationship with Other Party's Lawyer.

A member shall not represent a client in a matter in which another party's lawyer is a spouse, parent, child, or sibling of the member, lives with the member, is a client of the member, or has an intimate personal relationship with the member, unless the member informs the client in writing of the relationship.

This rule sets forth several specific relationships between attorneys representing adverse parties which must be disclosed to the clients. The fact that an attorney has acted or is acting as an expert witness for opposing party's counsel is not required to be disclosed under Rule 3-320.

Rules 3-310, entitled "Avoiding the Representation of Adverse Interests," requires the informed written consent of the client "if the member [of the Bar] has or had a relationship with another party interested in the representation." It would be a strained interpretation of this language to read it to include the opposing counsel as a "party interested in the representation." It is this Committee's opinion that this Rule was not intended to require disclosure of the past or continuing expert witness relationship.

Although the ABA Model Rules of Professional Conduct are not binding authority for California lawyers, it can be looked to for guidance. California Rule of Professional Conduct 1-100 and California State Bar Formal Opinion 1983-71. (1)

Under ABA Model Rule 1-7(b) (2), if the attorney's own interest may materially limit the attorney's ability to represent the client, the relationship must be disclosed. Further, even if the client gives written consent, the attorney may only representation the client if the attorney reasonably believes that the attorney's own interests will not adversely affect the representation of the client.

An attorney owes the highest duty of loyalty to his or her client. This duty alone requires attorneys to exercise caution in any circumstance in which the attorney's own interests might influence the attorney's representation of a client.

An attorney's representation of a client may be adversely affected by the attorney's own interests in situations in which the attorney might limit his or her actions due to the attorney's reluctance to alienate opposing counsel. These situations should be very rare. For example, if Attorney were currently acting as an expert witness for Law Firm in case #1, or if Attorney has acted as expert for Law Firm, on one or more occasions in the past, but with some expectation of future employment as an expert by Law Firm, then there is more likelihood that the attorney's own financial interests might limit his or her actions in representing the client.(3) If, on the other hand, Attorney has no reason to expect any future employment as expert for Law Firm, it would seem to be less likely that Attorney's own economic interests would affect the representation of the client.

For purposes of this discussion, it makes no difference whether the attorney is representing the client in a litigation or transactional matter.

If another attorney in Attorney's firm is now representing Client, California rules impose no duty of disclosure. Again, however, if the representation of the Client may be adversely affected by Attorney's relationship with Law Firm, then the duty of loyalty to Client may dictate disclosure under some circumstances. Attorneys should analyze the facts and circumstances of their own situations to determine whether disclosure would be appropriate.

This opinion is advisory only. It is not binding on the State Bar, the Board of Governors, its agents or employees.

  1. Local federal court rules in some districts require attorneys practicing in that district to abide by the ABA Model Rules.

  2. ABA Model Rule 1-7(b):

    (b) A lawyer shall not represent a client if the representation of that client may be materially limited by the lawyer's responsibilities to another client or to a third person, or by the lawyer's own interests, unless:

    (1) the lawyer reasonably believes the representation will not be adversely affected; and

    (2) the client consents after consultation.

    When representation of multiple clients in a single matter is undertaken, the consultation shall include explanation of the implications of the common representation and the advantages and risks involved. (Emphasis added.)

  3. Model Rule 1-7(b) would require that Attorney disclose the relationship and obtain client consent under these circumstances, and the attorney would also need to have a reasonable belief that the representation would not be affected by the attorney's relationship with Law Firm.


Disclaimer: This opinion was issued by the Legal Ethics Committee of the San Diego County Bar Association. It is advisory only and is not binding upon any member of the SDCBA, any other member of the State Bar of California, the State Bar of California or its Board of Governors, or any persons or tribunals charged with regulatory responsibilities. The SDCBA, its officers, directors, agents, and the Legal Ethics Committee members assume no responsibility or liability in rendering this opinion.