dissenting.
For substantially the reasons stated in Parts I and II of Justice Blackmun’s thoughtful concurrence, I believe that the Court of Appeals was correct to conclude that respondent was entitled to a new trial if he could demonstrate a “ ‘reasonable possibility that he was prejudiced’” by the double jeopardy violation, Mathews v. Marshall, 754 F. 2d 158, 162 (CA6 1985) (quoting Graham v. Smith, 602 F. 2d 1078, 1083 (CA2 1979)). This standard is consistent with the approach this Court has uniformly taken when constitutional violations do not require automatic reversal, see ante, at 250-253, and is justified by the difficulties that a defendant wishing to show even the probability of actual prejudice must face.
“There [can] never be any certainty as to whether the jury was actually influenced by the unconstitutionally broad scope of the reprosecution or whether the accused’s defense strategy was impaired by this scope of the charge, even if there were a most sensitive examination of the entire trial record and a more suspect and controversial inquest of the jurors still alive and available.” United States ex rel. Hetenyi v. Wilkins, 348 F. *2592d 844, 864 (CA2 1965), cert. denied sub nom. Mancusi v. Hetenyi, 383 U. S. 913 (1966).
The mere absence of any danger in a particular case that the bringing of a jeopardy-barred charge resulted in a compromise verdict, see, e. g., Price v. Georgia, 398 U. S. 323 (1970); Hetenyi, supra, is no reason for adopting a different standard for determining whether a defendant is entitled to a new trial. By impermissibly expanding the scope of the prosecution, the double jeopardy violation may have exposed defendant to serious dangers of another sort.
One of the dangers faced by respondent here was that evidence that would not have been admitted (indeed, might not have even been offered) had he been tried for simple murder came in because the prosecution had brought the jeopardy-barred charge of aggravated murder. The Court of Appeals reversed respondent’s conviction because it found that such otherwise inadmissible evidence had been admitted and “may have prejudiced the jury with regard to its findings as to intent and to the act itself.” 754 F. 2d, at 162. Unlike Justice Blackmun, I see no reason why the Court of Appeals should be required to reconsider its conclusion that respondent was so prejudiced. On such a question of state evidentiary law, “the federal judges who deal regularly with questions of state law in their respective districts and circuits are in a better position than we to determine how local courts would dispose of comparable issues,” Butner v. United States, 440 U. S. 48, 58 (1979). And, in the absence of any indication that the Court of Appeals gave anything less than its full attention to the question whether certain evidence that in fact came in would have been inadmissible in a simple murder trial, I believe that the majority’s decision to remand the case for a “more thorough consideration by the lower court” of this issue, ante, at 248, is disingenuous at best.