concurring.
I write separately to explain in more detail why I conclude that the trial judge erred by applying a “harmless beyond a reasonable doubt” test to this grand jury error.
The principle behind any harmless-error rule (no matter how formulated) is the idea that the presence of error, by itself, is not sufficient to invalidate the result reached in a judicial proceeding. Error having been proved, the reviewing court must still determine whether the losing side was prejudiced by this error. Love v. State, 457 P.2d 622, 630 (Alaska 1969).
When error arises in a criminal prosecution from a violation of the defendant’s rights under the United States Constitution, federal law requires reversal of the defendant’s conviction unless the government shows that the error is harmless beyond a reasonable doubt. Chapman v. California, 386 U.S. 18, 23-24, 87 S.Ct. 824, 827-28, 17 L.Ed.2d 705, 710-11 (1967). But the states are free to apply their own harmless-error rules when an error does not violate a defendant’s federal constitutional rights. Love, 457 P.2d at 631.
The question, then, is whether a criminal defendant has a federal constitutional right to require the exclusion of illegally obtained evidence from a grand jury proceeding. “Although the Supreme Court has not answered this precise question, there is little doubt from the manner in which the Court has dealt with very similar issues that the answer is no.” Wayne R. LaFave, Search and Seizure: A Treatise on the Fourth Amendment (3rd ed. 1996), § 1.6(c), Vol. 1, p. 163. See United States v. Calandra, 414 U.S. 338, 94 S.Ct. 613, 38 L.Ed.2d 561 (1974) (indicating that a defendant is not entitled to challenge an indictment on the ground that the grand jury heard evidence obtained in violation of the Fourth Amendment); United States v. Blue, 384 U.S. 251, 86 S.Ct. 1416, 16 L.Ed.2d 510 (1966) (indicating that a defendant is not entitled to challenge an indictment on the ground that the grand jury heard evidence obtained in violation of the Fifth Amendment privilege against self-incrimination); Lawn v. United States, 355 U.S. 339, 78 S.Ct. 311, 2 L.Ed.2d 321 (1958) (indicating the same). See also Costello v. United States, 350 U.S. 359, 76 S.Ct. 406, 100 L.Ed. 397 (1956) (upholding an indictment based entirely on hearsay evidence against a challenge under the confrontation clause of the Fifth Amendment).
Thus, even though evidence in this case was obtained in violation of Case’s privilege against self-incrimination, the introduction of that evidence at a grand jury proceeding (as distinct from a criminal trial) did not violate Case’s federal constitutional rights. This being so, the courts of this state are free to use Alaska’s own standard of harmless error. The standard for determining the harmfulness or harmlessness of grand jury error is described in Stern v. State, 827 P.2d 442, 445-46 (Alaska App.1992).
Use of the Stem test to assess grand jury errors makes sense even when the error is of constitutional dimension. When a court assesses whether an error was prejudicial, the essential question to be asked is whether the error might have affected the result. “[T]he pivotal question is what the error might have meant to the jury.” Love, 457 P.2d at 630.
In judging whether a verdict might have been different, one important factor to consider is the degree of proof required by law to sustain that verdict. To return a guilty verdict in a criminal prosecution, the trier of fact (whether judge or jury) must be satisfied that the government has proved its case beyond a reasonable doubt. On the other hand, the government’s burden at grand jury is substantially lower. See Sheldon v. State, 796 P.2d 831, 837 (Alaska App.1990) (a grand jury “should not return an indictment unless ... satisfied that the evidence presented, if unexplained or uncontradieted, established] a probability of [the defendant’s] guilt”).
Because of this difference in the standards of proof, the power of a given error to alter the verdict in these two types of proceedings is likewise different. An error may be prejudicial in a criminal trial (where a reasonable possibility of innocence is sufficient to acquit the defendant) but nevertheless be harmless in a grand jury context (where the same *1243reasonable possibility of innocence is not suf-fieient to defeat an indictment).
Thus, the potential prejudice of erroneously admitted evidence at grand jury should be judged under the standard described in Stem. This is the standard that the superior court should have applied in the present case.