Catholic University Law Review


Privilege law can be frustrated by the complexity of modern legal actions involving ramified enterprises engaging with their peers. To protect such allied parties cooperating in litigation or other legal matters, courts have innovated doctrines extending discovery protections to such postures under the names of co-client, joint defense, and common interest privilege. The niceties of these doctrines have proven unclear, however, particularly in the challenging situation of competing companies whose collusion or combinations must be monitored for antitrust concerns. Following a thorough overview of each doctrine and identifying how they overlap and differ, a focused examination of multi-party privilege law in the District of Columbia Circuit, where such antitrust suits are often brought, reveals that its court of appeals has in fact laid the groundwork for a comprehensive and consistent understanding of common interest privilege.