dissenting.
“In the interest of uniformity in criminal procedure within the circuit,” the Court of Appeals affirmed the District Court’s decision to suppress respondent’s grand jury testimony.* The Court of Appeals explicitly disclaimed a constitutional basis for its holding. Its action was taken “pursuant to [its] supervisory function.” 531 F. 2d 87, 90 (1976).
There is no reason to expect the Court of Appeals to reach a different result in light of our decision in United States v. Mandujano, 425 U. S. 564 (1976). Our holding that respondent would not have had a constitutional right to have her testimony suppressed simply has no bearing on a lower court *911decision which did not assume the existence of such a constitutional right. And it is clear that the well-established supervisory power of the courts of appeals over the district courts in their respective jurisdictions is not limited to enforcing constitutional rights. See, e. g., Cupp v. Naughten, 414 U. S. 141, 146 (1973); Barker v. Wingo, 407 U. S. 514, 530 n. 29 (1972); United States v. Thomas, 146 U. S. App. D. C. 101, 109-111, 449 F. 2d 1177, 1185-1187 (1971) (en banc); cf., e. g., Ristaino v. Ross, 424 U. S. 589, 597 n. 9 (1976); Murphy v. Florida, 421 U. S. 794, 797-798 (1975); id., at 804 (Burger, C. J., concurring).
Accepting the Government’s suggestion that we vacate and remand so that the Court of Appeals can reconsider its decision in light of an irrelevant case is a waste of the time of two courts. I respectfully dissent.
The Court of Appeals determined that it is the universal practice of United States Attorneys in the Second Circuit to warn a grand jury witness who is the target of an investigation. Respondent was called before the grand jury by a Strike Force attorney operating in the Eastern District of New York but based in Washington. She received no warning.