What is the current state of the law in the context of eavesdropping allegations?

Appellant proposes that we adopt a rule that, when a defendant makes a prima facie showing of eavesdropping, "prison officials should not be permitted to offer any rebuttal evidence." He points to the difficulty of countering self-serving testimony of prison officials and "the need to discourage planting 'bugs' in the first place." While we recognize the relevance of these considerations, appellant's rule would have the effect of treating a prima facie case as irrebuttable proof of a fact. Such a procedure would offend the basic principle that trial should be based on proof rather than speculation from an incomplete record. Barber v. Municipal Court, supra, 24 Cal.3d 742, which appellant cites, lends no support for this novel procedure. The issue there was whether the proven intrusion of a law enforcement agent into attorney-client conferences required dismissal of the underlying charges.

The trial court took the position that, once appellant made a prima facie case of eavesdropping, the burden of proof shifted to the prosecution to [217 Cal.App.3d 645] prove the legality of its conduct. Although we have not found any California authority directly on point, this procedure appears reasonable. The prosecution cannot be expected to negate all possible improprieties; the burden must be on the defendant to bring forward evidence supporting the claim of a Sixth Amendment violation. But when the defendant has made a showing from which a violation may reasonably be inferred, it is consistent with the procedure followed in Fourth Amendment cases to place on the prosecution the burden of proving the legality of its conduct. (Blair v. Pitchess (1971) 5 Cal.3d 258, 274, 96 Cal.Rptr. 42, 486 P.2d 1242.)

The remaining question concerns the nature of the prosecution's burden of proof. The trial court evidently assumed that the prosecution was required to prove the absence of eavesdropping beyond a reasonable doubt. This standard has been applied in cases involving the prejudicial effect of proven constitutional error (Chapman v. California, supra, 386 U.S. 18) or the issue of guilt or innocence. (United States v. Hermosillo-Nanez (9th Cir.1976) 545 F.2d 1230, cert. denied, 429 U.S. 1050, 97 S.Ct. 763, 50 L.Ed.2d 767; United States v. Glassel (9th Cir.1973) 488 F.2d 143, 146, cert. denied 416 U.S. 941, 94 S.Ct. 1945, 40 L.Ed.2d 292.) But it is inappropriate for a determination of whether a constitutional right has been violated when the issue has no necessary connection to the question of guilt.