dissenting.
Without discussion of the competing state and federal interests involved, the Court holds that a federal law enforcement officer should be enjoined from turning over to state authorities for use in a state prosecution evidence which he has obtained in contravention of the Fourth Amendment, and from giving testimony concerning the evidence in the state proceedings. This holding so far departs from the concepts which have hitherto been considered to govern state and federal relationships in this area that I am constrained to dissent.
1. The holding that an injunction should issue against making available to New Mexico the evidence and testimony in question is rested on this Court's “supervisory powers over federal law enforcement agencies.” So far as I know, this is the first time it has been suggested that the federal courts share with the executive branch of the Government responsibility for supervising law enforcement activities as such. McNabb v. United States, 318 U. S. 332, cited by the Court, stands for no such proposition. Indeed, in excluding the McNabb evidence in a federal trial, the Court was careful to say: . . we confine ourselves to our limited function as the court of ultimate review of the standards formulated and applied by federal courts in the trial of criminal cases. We are not concerned with law enforcement practices except in so far as courts themselves become instruments of law *219enforcement.” 318 U. S., at 347. I do not think that this case can be brought within McNabb simply because the enjoined evidence was seized under an invalid court process. Would the Court’s decision have been different had there been no search warrant at all? Moreover, the Court has heretofore refused to extend the McNabb rule to state criminal trials. Stein v. New York, 346 U. S. 156, 186-188; Gallegos v. Nebraska, 342 U. S. 55, 63-64.
2. Nor can this decision be supported under any general equity power. For although the federal courts undeniably have the power to issue an injunction in this case, they also have the discretion to withhold equitable relief when, on the balance, the power should not be exercised. On that basis, I think the decision cannot be reconciled with the rationale of Stefanelli v. Minard, 342 U. S. 117. There, in a case brought under the Civil Rights Act, R. S. § 1979, now 42 U. S. C. § 1983, claiming violation of petitioner’s rights under the Fourteenth Amendment, the Court refused to enjoin the use of state-seized evidence in a state prosecution, saying that “the federal courts should refuse to intervene in State criminal proceedings to suppress the use of evidence even when claimed to have been secured by unlawful search and seizure.” Id., at 120. That holding was based on the “special delicacy of the adjustment to be preserved between federal equitable power and State administration of its own law.” The same consideration is applicable here. The Court distinguishes Stejanelli because we are “not asked to enjoin state officials nor in any way to interfere with state agencies in enforcement of state law.” But this.seems to me illusory, for, as the Court recognizes, the State’s case against petitioner appears to depend wholly on the evidence in question; the injunction will operate quite as effectively, albeit indirectly, to stultify the state prosecution as if it had been issued directly against New Mexico or its officials. New Mexico’s prosecution is at least as *220far advanced as was the state prosecution in Stefanelli. If New Mexico should now seek to subpoena the federal agent, would the Court permit him to honor the State's process? And if not, how could that properly be said not to impinge directly upon the New Mexico prosecution? Today’s decision represents a reversal of the sound policy followed in Stefanelli; I can find no justification for it. It was not an abuse of discretion to withhold the relief here.
3. It is said that the federal policies against unlawful searches and seizures will be flouted if a federal agent can “use the fruits of his unlawful act either in federal or state proceedings.” But this Court has already held that although the substance of the Fourth Amendment is “implicit in 'the concept of ordered liberty’ ” and hence enforceable against the States through the Fourteenth Amendment, evidence unlawfully seized by a State can nevertheless be used in state prosecutions. Wolf v. Colorado, 338 U. S. 25. That being so, I am unable to understand how an exercise of federal equity power designed to deny the State the use of this evidence can be squared with the policies underlying Wolf. The fact that the injunction operates only against evidence still in possession of the federal authorities and against testimony by a federal officer is for me not a sufficient answer, since the only difference I can see between the Wolf decision and Weeks v. United States, 232 U. S. 383, excluding in federal criminal trials evidence obtained in contravention of the Fourth Amendment, is the difference between state and federal courts; in each case, the substance of the constitutional command is the same, but the nature of enforcement varies with the forum. So that, had the petitioner here been convicted in the state courts by use of this evidence, I take it that Wolf means we would not have interfered, at least absent any showing of a more aggravated search and seizure than this record discloses. To say that *221federal interference is nevertheless justified at this point in the proceedings whenever the State has not yet obtained the evidence seems to me to make the matter simply a race between a state prosecution and a federal injunction proceeding. I do not believe that a rule dependent on the fortuitous circumstance of winning that race is a sound one in this important field of federal-state relations. If, on the other hand, the Court is now saying that it is the difference between the Fourth Amendment and the Fourteenth which requires this result — a conclusion disclaimed by the majority — then I would still regard the injunction as improvidently issued, since New Mexico should be given the first opportunity to suppress the evidence, with this Court sitting in review if the State improperly refuses to do so. Cf. Douglas v. Jeannette, 319 U. S. 157.
In accommodating state and federal interests in criminal law enforcement, this Court has hitherto taken the view that the States should be left free to follow or not the federal exclusionary rule set forth in Weeks v. United States, supra. The present decision seems to me to be a step in the opposite and wrong direction. I think the judgment below should be affirmed.