Except for litigants involved in federal question cases (who must look to federal common law for privilege guidance), every litigant facing a privilege question must determine which state’s privilege law applies. Once they determine through choice of laws rules which state’s privilege law applies, they must then look for that state’s law.
Some states express their privilege law through statutes, while others look exclusively to the common law. Other states use a mixture. For instance, in Cline v. Reliance Trust Co., No. 1:04-CV-02079, 2005 U.S. Dist. LEXIS 26066, at *7 (N.D. Ohio Oct. 31, 2005 ), the court explained that “Ohio’s attorney-client privilege laws can be found both in the Ohio Revised Code and in the common law of the state.” On the very next day, a Pennsylvania court made the same observation about Pennsylvania privilege law. In re Investigating Grand Jury, 2005 PA Super. 369 ( Pa. Super. Ct. 2005).
Except for a handful of states’ continued recognition of the “control group” approach to privilege, most states follow essentially the same attorney-client privilege law. Still, litigants must be prepared to find the pertinent state’s law wherever it is.