When the government can keep an informer's identity secret

Supreme Court proposal for Rule 510, see Rules of Evidence for U.S. Courts and Magistrates as promulgated by the U.S. Supreme Court, 28 App. U.S. Code Service, App. 6 (1975). The original Advisory Committee's Note says: "The rule recognizes the use of informers as an important aspect of law enforcement, whether the informer is a citizen who steps forward with information or a paid undercover agent. In either event, the basic importance of anonymity in the effective use of informers is apparent ... and the privilege of withholding their identity was well established at common law." The intent of the rule is to balance the necessity for effective law enforcement machinery and the requirement of constitutional safeguards for the defendant. The rule restates existing law. In McCray v. Illinois, 386 U.S. 300 (1967), the court held that no constitutional requirement dictated disclosure of the identity of an informant for the sole purpose of challenging a finding of probable cause for issuance of a search or arrest warrant. See also United States v. Harris, 403 U.S. 573 (1971). The Hawaii Supreme Court has ruled similarly. In State v. Delaney, 58 H. 19, 24, 563 P.2d 990, 994 (1977), the court held: "[N]either the federal nor state constitutions dictate disclosure of an informer's identity where the sole purpose is to challenge the finding of probable cause. A trial court may, in its discretion, require disclosure if it believes that the officer's testimony [regarding the informer] is inaccurate or untruthful." Relying on McCray v. Illinois, supra, and the previous decision in State v. Texeira, 50 H. 138, 433 P.2d 593 (1967), the Delaney court also held that the trial court properly disallowed questions that might indirectly disclose the informer's identity. Subsection (c)(2) of this rule deals with the situation where the informant can supply testimony relevant to the merits of a criminal or civil case. In this situation disclosure is ordinarily required, see Roviaro v. United States, 353 U.S. 53 (1957), cf. Smith v. Illinois, 390 U.S. 129 (1968).