I. CLIENT-LAWYER RELATIONSHIP
Rule 1.09 Conflict of Interest: Former Client
(a) Without prior consent, a lawyer who personally has formerly represented a client in a matter shall not thereafter represent another person in a matter adverse to the former client:
(1) in which such other person questions the validity of the lawyer's services or work product for the former client;
(2) if the representation in reasonable probability will involve a violation of Rule 1.05; or
(3) if it is the same or a substantially related matter.
(b) Except to the extent authorized by Rule 1.10 , when lawyers are or have become members of or associated with a firm , none of them shall knowingly represent a client if any one of them practicing alone would be prohibited from doing so by paragraph (a).
(c) When the association of a lawyer with a firm has terminated, the lawyers who were then associated with that lawyer shall not knowingly represent a client if the lawyer whose association with that firm has terminated would be prohibited from doing so by paragraph (a)(l) or if the representation in reasonable probability will involve a violation of Rule 1.05.
Comment - Rule 1.09
1. Rule 1.09 addresses the circumstances in which a lawyer in private practice, and other lawyers who were, are or become members of or associated with a firm in which that lawyer practiced or practices, may represent a client against a former client of that lawyer or the lawyer's former firm. Whether a lawyer, or that lawyer's present or former firm is prohibited from representing a client in a matter by reason of the lawyer's successive government and private employment is governed by Rule 1.10 rather than by this Rule.
2. Paragraph (a) concerns the situation where a lawyer once personally represented a client and now wishes to represent a second client against that former client. Whether such a personal attorney-client relationship existed involves questions of both fact and law that are beyond the scope of these Rules. See Preamble: Scope. Among the relevant factors, however, would be how the former representation actually was conducted within the firm; the nature and scope of the former client's contacts with the firm (including any restrictions the client may have placed on the dissemination of confidential information within the firm); and the size of the firm.
3. Although paragraph (a) does not absolutely prohibit a lawyer from representing a client against a former client, it does provide that the latter representation is improper if any of three circumstances exists, except with prior consent. The first circumstance is that the lawyer may not represent a client who questions the validity of the lawyer's services or work product for the former client. Thus, for example, a lawyer who drew a will leaving a substantial portion of the testator's property to a designated beneficiary would violate paragraph (a) by representing the testator's heirs at law in an action seeking to overturn the will.
4. Paragraph (a)'s second limitation on undertaking a representation against a former client is that it may not be done if there is a "reasonable probability" that the representation would cause the lawyer to violate the obligations owed the former client under Rule 1.05. Thus, for example, if there were a reasonable probability that the subsequent representation would involve either an unauthorized disclosure of confidential information under Rule 1.05 (b) (l) or an improper use of such information to the disadvantage of the former client under Rule 1.05 (b) (3) , that representation would be improper under paragraph (a). Whether such a reasonable probability exists in any given case will be a question of fact.
4. The third situation where representation adverse to a former client is prohibited is where the representation involves the same or a substantially related matter. The "same" matter aspect of this prohibition prevents a lawyer from switching sides and representing a party whose interests are adverse to a person who sought in good faith to retain the lawyer. It can apply even if the lawyer declined the representation before the client had disclosed any confidential information. This aspect of the prohibition includes, but is somewhat broader than, that contained in paragraph (a) (1) of this Rule. The "substantially related" aspect, on the other hand, has a different focus. Although that term is not defined in the Rule, it primarily involves situations where a lawyer could have acquired confidential information concerning a prior client that could be used either to that prior client's disadvantage or for the advantage of the lawyer's current client or some other person. It thus largely overlaps the prohibition contained in paragraph (a) (2) of this Rule.
5. Paragraph (b) extends paragraph (a)'s limitations on an individual lawyer's freedom to undertake a representation against that lawyer's former client to all other lawyers who are or become members of or associated with the firm in which that lawyer is practicing. Thus, for example, if a client severs the attorney-client relationship with a lawyer who remains in a firm, the entitlement of that individual lawyer to undertake a representation against that former client is governed by paragraph (a); and all other lawyers who are or become members of or associated with that lawyer's firm are treated in the same manner by paragraph (b). Similarly, if a lawyer severs his or her association with a firm and that firm retains as a client a person whom the lawyer personally represented while with the firm, that lawyer's ability thereafter to undertake a representation against that client is governed by paragraph (a); and all other lawyers who are or become members of or associates with that lawyer's new firm are treated in the same manner by paragraph (b).
6. Paragraph (c) addresses the situation of former partners or associates of a lawyer who once had represented a client when the relationship between the former partners or associates and the lawyer has been terminated. In that situation, the former partners or associates are prohibited from questioning the validity of such lawyer's work product and from undertaking representation which in reasonable probability will involve a violation of Rule 1.05. Such a violation could occur, for example, when the former partners or associates retained materials in their files from the earlier representation of the client that, if disclosed or used in connection with the subsequent representation, would violate Rule 1.05(b)(1) or (b)(3).
7. Thus, the effect of paragraph (b) is to (a) extend any inability of a particular lawyer under paragraph (a) to undertake a representation against a former client to all other lawyers who are or become members of or associated with any firm in which that lawyer is practicing. If, on the other hand, a lawyer disqualified by paragraph (a) should leave a firm, paragraph (c) prohibits lawyers remaining in that firm from undertaking a representation that would be forbidden to the departed lawyer only if that representation would violate sub-paragraphs (a) (1) or (a) (2). Finally, should those other lawyers cease to be members of the same firm as the lawyer affected by paragraph (a) without personally coming within its restrictions, they thereafter may undertake the representation against the lawyer's former client unless prevented from doing so by some other of these Rules.
8. Although not required to do so by Rule 1.05 or this Rule, some courts, as a procedural decision, disqualify a lawyer for representing a present client against a former client when the subject matter of the present representation is so closely related to the subject matter of the prior representation that confidences obtained from the former client might be useful in the representation of the present client. See Comment 17 to Rule 1.06. This so-called "substantial relationship" test is defended by asserting that to require a showing that confidences of the first client were in fact used for the benefit of the subsequent client as a condition to procedural disqualification would cause disclosure of the confidences that the court seeks to protect. A lawyer is not subject to discipline under Rule 1.05(b)(1), (3), or (4), however, unless the protected information is actually used. Likewise, a lawyer is not subject to discipline under this Rule unless the new representation by the lawyer in reasonable probability would result in a violation of those provisions.
9. Whether the "substantial relationship" test will continue to be employed as a standard for procedural disqualification is a matter beyond the scope of these Rules. See Preamble: Scope. The possibility that such a disqualification might be sought by the former client or granted by a court, however, is a matter that could be of substantial importance to the present client in deciding whether or not to retain or continue to employ a particular lawyer or law firm as its counsel. Consequently, a lawyer should disclose those possibilities, as well as their potential consequences for the representation, to the present client as soon as the lawyer becomes aware of them; and the client then should be allowed to decide whether or not to obtain new counsel. See Rules 1.03(b) and 1.06(b).
10. This Rule is primarily for the protection of clients and its protections can be waived by them. A waiver is effective only if there is consent after disclosure of the relevant circumstances, including the lawyer's past or intended role on behalf of each client, as appropriate. See Comments 7 and 8 to Rule 1.06.