A municipal attorney who advised a department head in his official capacity at a deposition in a lawsuit between two private parties may represent the municipality in an “unrelated” lawsuit brought by that department head against the municipality subsequent to his departure from municipal employment and may introduce the deposition testimony to impeach the former department head.
Facts: A municipal attorney accompanied a department head to a deposition in a lawsuit between two private parties and in that connection advised the department head only in his official capacity. Subsequently, the department head left his position and brought suit against the municipality. While the municipality states that this suit is unrelated to the previous private suit, it also says that the deposition transcript may be useful to impeach the former department head. The municipal attorney has no relevant confidential information of the department head. The attorney inquires whether his representation of the municipality in the present lawsuit by the former department head may violate Rules 1.9(a) and 1.9(c) of the Massachusetts Rules of Professional Conduct.
Rule 1.9(a) provides:
A lawyer who has formerly represented a client in a matter shall not thereafter represent another person in the same or a substantially related matter in which that person’s interests are materially adverse to the interests of the former client unless the former client consents after consultation.
Rule 1.9(c ) provides:
A lawyer who has formerly represented a client in a matter or whose present or former firm has formerly represented a client in a matter shall not thereafter, unless the former client consents after consultation:
(1) use confidential information relating to the representation to the disadvantage of the former client, to the lawyer’s advantage, or to the advantage of a third person, except as Rule 1.6, Rule 3.3, or Rule 4.1 would permit or require with respect to a client; or
(2) reveal confidential information relating to the representation except as Rule 1.6 or Rule 3.3 would permit or require with respect to a client.
In deciding whether these Rules are applicable, the key issue is to identify the “former client.” In that regard, the relevant Rule of professional conduct is Rule 1.13. Rule 1.13 and Comments provide:
RULE 1.13 ORGANIZATION AS CLIENT
(a) A lawyer employed or retained by an organization represents the organization acting through its duly authorized constituents. . . .
(d) In dealing with an organization’s directors, officers, employees, members, shareholders, or other constituents, a lawyer shall explain the identity of the client when it is apparent that the organization’s interests are adverse to those of the constituents with whom the lawyer is dealing.
(e) A lawyer representing an organization may also represent any of its directors, officers, employees, members, shareholders, or other constituents, subject to the provisions of Rule 1.7. If the organization’s consent to the dual representation is required by Rule 1.7, the consent shall be given by an appropriate official of the organization other than the individual who is to be represented, or by the shareholders.
The Entity as the Client
 An organizational client is a legal entity, but it cannot act except through its officers, directors, employees, shareholders and other constituents. Officers, directors, employees and shareholders are the constituents of the corporate organizational client. The duties defined in this Comment apply equally to unincorporated associations. “Other constituents” as used in this Comment means the positions equivalent to officers, directors, employees and shareholders held by persons acting for organizational clients that are not corporations.
 When one of the constituents of an organizational client communicates with the organization’s lawyer in that person’s organizational capacity, the communication is protected by Rule 1.6. Thus, by way of example, if an organizational client requests its lawyer to investigate allegations of wrongdoing, interviews made in the course of that investigation between the lawyer and the client’s employees or other constituents are covered by Rule 1.6. This does not mean, however, that constituents of an organizational client are the clients of the lawyer. The lawyer may not disclose to such constituents information relating to the representation except for disclosures explicitly or impliedly authorized by the organizational client in order to carry out the representation or as otherwise permitted by Rule 1.6. . . .
 The duty defined in this Rule applies to governmental organizations. However, when the client is a governmental organization, a different balance may be appropriate between maintaining confidentiality and assuring that the wrongful official act is prevented or rectified, for public business is involved. In addition, duties of lawyers employed by the government or lawyers in military service may be defined by statutes and regulation. Therefore, defining precisely the identity of the client and prescribing the resulting obligations of such lawyers may be more difficult in the government context. Although in some circumstances the client may be a specific agency, it is generally the government as a whole. For example, if the action or failure to act involves the head of a bureau, either the department of which the bureau is a part or the government as a whole may be the client for purpose of this Rule. Moreover, in a matter involving the conduct of government officials, a government lawyer may have authority to question such conduct more extensively than that of a lawyer for a private organization in similar circumstances. This Rule does not limit that authority. See note on Scope.
Clarifying the Lawyer’s Role
 There are times when the organization’s interest may be or become adverse to those of one or more of its constituents. In such circumstances the lawyer should advise any constituent, whose interest the lawyer finds adverse to that of the organization of the conflict or potential conflict of interest, that the lawyer cannot represent such constituent, and that such person may wish to obtain independent representation. Care must be taken to assure that the individual understands that, when there is such adversity of interest, the lawyer for the organization cannot provide legal representation for that constituent individual, and that discussions between the lawyer for the organization and the individual may not be privileged.
As indicated in Rule 1.13(a), a municipal attorney represents the municipality, and on occasion its various departments. Of course, the municipality can only speak through its agents, but a municipal attorney who advises individual agents does so only in their official capacity. We are assuming that the responsibilities of lawyers for the municipality in that regard have been explained to the various municipal officials with whom they work and that the former department head could not reasonably have concluded that the municipal attorney was representing him personally in connection with his deposition. In that situation, the lawyer’s client was still the municipality or the municipal department, acting through its agent. Just like any other legal entity in a similar situation, the municipality controlled the attorney-client privilege and the lawyer’s confidentiality obligation, and the loyalty obligation of the lawyer ran to the municipality and not, in any individual sense, to the department head who was being deposed. If the department head had testified to any impropriety, the lawyer would have been obligated to reveal that information to the appropriate municipal official despite any contrary instruction from the department head.
Based on this analysis and the assumptions we have made above, then in our view Rules 1.9(a) and (c) do not apply. The municipal lawyer never represented the former department head as an individual. The former client was the municipality. The municipal attorney who accompanied the former department head to the deposition would not be changing sides in defending the municipality against suit by the former department head. He represented the city municipality before and would still be representing the municipality. He would therefore be entitled, on behalf of the municipality, to use testimony given by the former department head in his official capacity to impeach subsequent testimony by the former head in his suit against the municipality without violating any of the Rules of Professional Conduct.
This advice is that of a Committee without official governmental status.