What is the legal test for disclosing the identity of a confidential informant in a criminal case?

While a defendant who demonstrates he or she has been entrapped is not required to negate one of the elements of the crime, and therefore may not be "innocent" of the crime, the defense of entrapment is exculpatory to the same degree as any other defense. If a jury finds that a crime has been committed as a result of entrapment, the defendant must be acquitted of the criminal charge. (See generally Sherman v. United States (1958) 356 U.S. 369, 373 [indictment must be dismissed when entrapment proven as a matter of law].) Further, the policy underlying informant disclosure does not depend on the technical innocence of the defendant. Rather, disclosure is required to satisfy defendants' due process right to know the identity of a witness whose testimony is "critical" to their defense, regardless of the nature of that defense. (California v. Trombetta (1984) 467 U.S. 479, 485.) For both these reasons, the prosecution was required to reveal the name of the confidential informant if there was a reasonable possibility he could provide evidence supporting a defense of entrapment. (See Twiggs v. Superior Court, supra, 34 Cal.3d at pp. 364, 365 [disclosure of informant's identity ordered when informant could testify regarding entrapment].)³

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