opinion: FONG FOO et al. v. UNITED STATES.
  No. 64.
  Argued January 16, 1962.
  Decided March 19, 1962
  Arthur Richenthal argued the causes for petitioners and filed briefs for petitioner in No. 65. David E. Feller filed briefs for petitioners in No. 64.
  Solicitor General Cox argued the causes for the United States. With him on the briefs were Assistant Attorney General Miller, Stephen J. Poliak, Beatrice Rosenberg, Philip R. Monahan and J. F. Bishop.
  Together with No. 65, Standard Coil Products Co., Inc., v. United States, also on certiorari to the same Court.
  Per Curiam.
  The petitioners, a corporation and two of its employees, were brought to trial before a jury in a federal district court upon an indictment charging a conspiracy and the substantive offense of concealing material facts in a matter within the jurisdiction of an agency of the United States, in violation of 18 U. S. C. §§ 371 and 1001. After seven days of what promised to be a long and complicated trial, three government witnesses had appeared and a fourth was in the process of testifying. At that point the district judge directed the jury to return verdicts of acquittal as to all the defendants, and a formal judgment of acquittal was subsequently entered.
  The record shows that the district judge’s action was based upon one or both of two grounds: supposed improper conduct on the part of the Assistant United States Attorney who was prosecuting the case, and a supposed lack of credibility in the testimony of the witnesses for the prosecution who had testified up to that point.
  The Government filed a petition for a writ of mandamus in the Court of Appeals for the First Circuit, praying that the judgment of acquittal be vacated and the case reassigned for trial. The court granted the petition, upon the ground that under the circumstances revealed by the record the trial court was without power to direct the judgment in question. Judge Aldrich concurred separately, finding that the directed judgment of acquittal had been based solely on the supposed improper conduct of the prosecutor, and agreeing with his colleagues that the district judge was without power to direct an acquittal on that ground. 286 F. 2d 556. We granted certiorari to consider a question of importance in the administration of justice in the federal courts. 366 U. S. 959.
  In holding that the District Court was without power to direct acquittals under the circumstances disclosed by the record, the Court of Appeals relied primarily upon two decisions of this Court, Ex parte United States, 242 U. S. 27, and Ex parte United States, 287 U. S. 241. In the first of these cases it was held that a district judge had no power to suspend a mandatory prison sentence, and that a writ of mandamus would lie to require the judge to vacate his erroneous order of suspension. In the second case the Court issued a writ of mandamus ordering a district judge to issue a bench warrant which he had refused to do, in the purported exercise of his discretion, for a person under an indictment returned by a properly constituted grand jury.
  Neither of those decisions involved the guaranty of the Fifth Amendment that no person shall “be subject for the same offence to be twice put in jeopardy of life or limb.” That constitutional provision is at the very root of the present case, and we cannot but conclude that the guaranty was violated when the Court of Appeals set aside the judgment of acquittal and directed that the petitioners be tried again for the same offense.
  The petitioners were tried under a valid indictment in a federal court which had jurisdiction over them and over the subject matter. The trial did not terminate prior to the entry of judgment, as in Gori v. United States, 367 U. S. 364. It terminated with the entry of a final judgment of acquittal as to each petitioner. The Court of Appeals thought, not without reason, that the acquittal was based upon an egregiously erroneous foundation. Nevertheless, “[t]he verdict of acquittal was final, and could not be reviewed . . . without putting [the petitioners] twice in jeopardy, and thereby violating the Constitution.” United States v. Ball, 163 U. S. 662, 671.
  Reversed.
  Ms. Justice Whittaker took no part in the consideration or decision of these cases.