Joint defense privilege

The joint defense privilege, or common-interest rule, is an extension of the attorney–client privilege. Under “common interest” or “joint defense” doctrine, parties with shared interest in actual or potential litigation against common adversary may share privileged information without waiving their right to assert attorney–client privilege. Because the joint defense "privilege sometimes may apply outside the context of actual litigation, what the parties call a ‘joint defense’ privilege is more aptly termed the ‘common interest’ rule.”

“The need to protect the free flow of information from client to attorney logically exists whenever multiple clients share a common interest about a legal matter.” The common interest rule serves to protect the confidentiality of communications passing from one party to the attorney for another party where a joint defense effort or strategy has been decided upon and undertaken by the parties and their respective counsel.

The joint defense privilege does not merely protect statements made by attorney to client or attorney to attorney. The privilege also is held to cover communications made to certain agents of an attorney, including accountants hired to assist in the rendition of legal services. Furthermore, a person need not be a litigant to be a party to a joint defense agreement. The joint defense privilege also applies to "parties or potential parties sharing a common interest in the outcome of a particular claim. Only those communications made in the course of an ongoing common enterprise and intended to further the enterprise are protected.

A party seeking to assert the joint defense privilege must demonstrate that:

For “common interest” or “joint defense” doctrine to apply, to permit parties with common interest in actual or potential litigation to share privileged information without waiving their right to assert privilege, parties' common interest must be identical and not merely similar, and must be legal and not solely commercial. Furthermore, the protection of the privilege “extends only to communications and not to facts.” While a client may refuse to answer questions regarding what it said or wrote to its attorney, it may not refuse to disclose relevant facts “merely because [it] incorporated a statement of such fact into [its] communication to [its] attorney.” The joint defense privilege, like the attorney–client privilege, does not protect “underlying facts embodied in a communication between attorney and client.”

Generally, a client waives the attorney–client privilege when he voluntarily discloses privileged communications to third party. Waiver under joint defense doctrine is essentially the same as that under attorney client privilege. The only difference is that a co-defendant’s communication with the other attorney is not a waiver of the confidentiality of that communication. Voluntary disclosure to a third party of purportedly privileged communications has long been considered inconsistent with the privilege. It is well settled that when a party voluntarily discloses privileged communications to a third party, the privilege is waived. Similarly, when a party discloses a portion of otherwise privileged material but withholds the remainder, the privilege is waived only as to those communications actually disclosed, unless a partial waiver would be unfair to the party's adversary. Disclosure alone, without intent, may constitute waiver of the attorney–client privilege. ... “under traditional waiver doctrine a voluntary disclosure ... to a third party waives the attorney–client privilege even if the third party agrees not to disclose the communications to anyone else.” In Massachusetts, when an attorney represents more than one client in a particular matter, one client's communication made to the attorney in the presence of the other client or clients is not privileged, as between the clients. In Thompson v. Cashman a lawyer who was acting for both plaintiff and defendant was allowed to testify to a conversation between the lawyer, plaintiff, and defendant. But not all disclosure results in waiver. “Under joint defense privilege, communications between client and his own lawyer remain protected by attorney–client privilege when disclosed to co-defendants or their counsel for purposes of common defense.”.

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Wikipedia