Informal Opinion Number: 20030007

Reference Note: Rule 4-1.9, Duties to Former Clients, was amended effective July 1, 2007. Rule 4-1.10, Imputation of Conflicts of Interest: General Rule, was amended effective July 1, 2007. This opinion is based on Rules 4-1.9 and 4-1.10 in effect prior to July 1, 2007.

QUESTION: An attorney recently joined the Attorney’s Firm. The attorney was previously employed at another firm which is opposing counsel in a number of cases. If the new attorney did not participate in a case at the other firm, does Attorney’s Firm have a conflict in that case? What if the new attorney is screened?
ANSWER: Rule 4-1.10 states, in part:
(b) When a lawyer becomes associated with a firm, the firm may not knowingly represent a person in the same or a substantially related matter in which that lawyer, or a firm with which the lawyer was associated, had previously represented a client whose interests are materially adverse to that person and about whom the lawyer had acquired information protected by Rules 1.6 and 1.9(b) that is material to the matter.

The Comment states, in part:

Paragraphs (b) and (c) operate to disqualify the firm only when the lawyer involved has actual knowledge of information protected by Rules 1.6 and 1.9(b). Thus, if a lawyer while with one firm acquired no knowledge of information relating to a particular client of the firm, and that lawyer later joined another firm, neither the lawyer individually nor the second firm is disqualified from representing another client in the same or a related matter even though the interests of the two clients conflict.

Independent of the question of disqualification of a firm, a lawyer changing professional association has a continuing duty to preserve confidentiality of information about a client formerly represented. See Rules 1.6 and 1.9.

Attorney has indicated that the attorney who was formerly with the other firm was not the attorney in the case and did not participate in the work up of the case for the defense. That information does not quite cover the necessary inquiry. The question is whether the attorney acquired any confidential information regarding the matter while the attorney was with the other firm. This could be information acquired by conferring on an issue related to the case, through informal conversation within the firm, etc. If the attorney acquired such information, Attorney’s Firm has a conflict and is disqualified, unless the attorney’s former client and Attorney’s Firm’s client consent, after consultation. Screening the attorney within Attorney’s Firm is not a means by which disqualification can be avoided. However, screening may help to persuade the former client to waive the conflict.

Informal Opinions are ethics advisory opinions issued by the Office of Legal Ethics Counsel to members of the Bar about Rule 4 (Rules of Professional Conduct), Rule 5 (Complaints and Proceedings Thereon), and Rule 6 (Fees to Practice Law) pursuant to Missouri Supreme Court Rule 5.30(c). Written summaries of select Informal Opinions are published for informational purposes as determined by the Advisory Committee of the Supreme Court of Missouri pursuant to Rule 5.30(c). Informal opinion summaries are advisory in nature and are not binding. These opinions are published as an educational service and do not constitute legal advice.

To request an Informal Opinion, please visit: https://mo-legal-ethics.org/for lawyers/requesting-an-informal-advisory-opinion/.

© Copyright 2025