JUSTICE BLACKMUN delivered the opinion of the Court.The Organized Crime Control Act of 1970, Pub.L. 91-452, 84 Stat. 922, contains, among other things, a definition of "dangerous special offender," 18 U.S.C. §§ 3575(e) and (f); [Footnote 1] authorizes the imposition of an increased sentence upon Page 449 U. S. 119 a convicted dangerous special offender, § 3575(b); and grants the United States the right, under specified conditions, to Page 449 U. S. 120 take that sentence to the Court of Appeals for review, § 3576. [Footnote 2]  The issue presented by this case is whether § 3576, Page 449 U. S. 121 authorizing the United States so to appeal, violates the Double Jeopardy Clause [Footnote 3] of the Fifth Amendment of the Constitution. [Footnote 4] Page 449 U. S. 122IAt a 1977 jury trial in the United States District Court for the Western District of New York, respondent Eugene DiFrancesco was convicted of conducting the affairs of an enterprise through a pattern of racketeering activity, and of conspiring to commit that offense, in violation of 18 U.S.C. §§ 1962(c) and (d). [Footnote 5]  At another jury trial in 1978 -- before a different judge in the same District -- based on an indictment returned prior to the racketeering indictment, respondent was convicted of damaging federal property, in violation of 18 U.S.C. § 1361, of unlawfully storing explosive materials, in violation of 18 U.S.C. § 842(j), and of conspiring to commit those offenses, in violation of 18 U.S.C. § 371. [Footnote 6]Respondent was first sentenced, in March, 1978, on his convictions at the later trial.  He received eight years on the charge for damaging federal property and five years on the conspiracy charge, these sentences to be served concurrently, and one year on the unlawful storage charge, to be served consecutively to the other sentences.  This made a total of nine years' imprisonment.  In April, respondent was sentenced as a dangerous special offender under § 3575 to two 10-year terms on the racketeering counts upon which he was convicted at the earlier trial; the court specified that these sentences were to be served concurrently with each other and with the sentences imposed in March.  The dangerous special Page 449 U. S. 123 offender charge and sentences thus resulted in additional punishment of only about a year.Respondent appealed the respective judgments of conviction to the Court of Appeals for the Second Circuit, and the United States sought review, under § 3576, of the sentences imposed upon respondent as a dangerous special offender.  The Court of Appeals unanimously affirmed the judgments of conviction.  By a divided vote, however, that court dismissed the Government's appeal on double jeopardy grounds.  604 F.2d 769 (1979).  The two judges in the majority thus did not address the merits of the special offender issue.  The third judge, while agreeing that the Government's appeal was to be dismissed, based that conclusion not on constitutional grounds, as did the majority, but on the grounds that §§ 3575 and 3576 were inapplicable to the facts of the case.  604 F.2d  at 787. [Footnote 7] Because of the importance of the constitutional question, we granted the Government's petition for certiorari, which confined itself to that single issue.  444 U.S. 1070 (1980).  Respondent has not filed a cross-petition.IIAt the earlier racketeering trial, the evidence showed that respondent was involved in an arson-for-hire scheme in the Rochester, N.Y., area that was responsible for at least eight fires between 1970 and 1973; that the ring collaborated with property owners to set fire to buildings in return for shares of the insurance proceeds; and that insurers were defrauded of approximately $480,000 as a result of these fires.  At the second trial, the evidence showed that respondent participated Page 449 U. S. 124 in the 1970 "Columbus Day bombings," including the bombing of the federal building at Rochester.Prior to the first trial, the Government, in accordance with § 3575(a), filed with the trial court a notice alleging that respondent was a dangerous special offender.  This notice recited the Government's intention to seek enhanced sentences on the racketeering counts in the event respondent was convicted at that trial.  After respondent was found guilty, a dangerous special offender hearing, pursuant to § 3575(b), was held.  At the hearing, the Government relied upon the testimony adduced at the trial and upon public documents that attested to other convictions of respondent for the Columbus Day bombings, for loansharking, and for murder.  App. 27-28, 30.  The defense offered no evidence.  It conceded the validity of the public records, id. at 31-32, but objected to any consideration of the murder offense because that conviction had been vacated on appeal.  Id. at 2-29.The District Court made findings of fact and ruled that respondent was a dangerous special offender within the meaning of the statute.  The findings set forth respondent's criminal record and stated that that record revealed"virtually continuous criminal conduct over the past eight years, interrupted only by relatively brief periods of imprisonment in 1975, 1976 and 1977."Id. at 41.  The court found, in addition, that respondent's"criminal history, based upon proven facts, reveals a pattern of habitual and knowing criminal conduct of the most violent and dangerous nature against the lives and property of the citizens of this community.  It further shows the defendant's complete and utter disregard for the public safety.  The defendant, by virtue of his own criminal record, has shown himself to be a hardened habitual criminal from whom the public must be protected for as long a period as possible.  Only in that way can the public be protected from further violent and dangerous criminal Page 449 U. S. 125 conduct by the defendant."Id. at 43. [Footnote 8]  The court thereupon sentenced respondent under § 3575(b) to the concurrent 10-year terms hereinabove described.   App. 456.The United States then took its appeal under § 3576, claiming that the District Court abused its discretion in imposing sentences that amounted to additional imprisonment of respondent for only one year, in the face of the findings the court made after the dangerous special offender hearing. [Footnote 9]  Page 449 U. S. 126 The dismissal of the Government's appeal by the Court of Appeals rested specifically upon its conclusion, which it described as "inescapable," that"to subject a defendant to the risk of substitution of a greater sentence, upon an appeal by the government, is to place him a second time 'in jeopardy of life or limb.'"604 F.2d  at 783.IIIWhile this Court, so far as we are able to ascertain, has never invalidated an Act of Congress on double jeopardy grounds, it has had frequent occasion recently to consider and pass upon double jeopardy claims raised in various contexts.  See United States v. Jorn, 400 U. S. 470 (1971); Colten v. Kentucky, 407 U. S. 104 (1972); Illinois v. Somerville, 410 U. S. 458 (1973); Chaffin v. Stynchcombe, 412 U. S. 17 (1973); United States v. Wilson, 420 U. S. 332 (1975); United States v. Jenkins, 420 U. S. 358 (1975); Serfass v. United States, 420 U. S. 377 (1975); Breed v. Jones, 421 U. S. 519 (1975); United States v. Dinitz, 424 U. S. 600 (1976); Ludwig v. Massachusetts, 427 U. S. 618 (1976); United States v. Martin Linen Supply Co., 430 U. S. 564 (1977); Lee v. United States, 432 U. S. 23 (1977); Arizona v. Washington, 434 U. S. 497 (1978); Burks v. United States, 437 U. S. 1 (1978); Greene v. Massey, 437 U. S. 19 (1978); Crist v. Bretz, 437 U. S. 28 (1978); Sanabria v. United States, 437 U. S. 54 (1978); United States v. Scott, 437 U. S. 82 Page 449 U. S. 127 (1978); Swisher v. Brady, 438 U. S. 204 (1978); Whalen v. United States, 445 U. S. 684 (1980); Illinois v. Vitale, 447 U. S. 410 (1980).These cited cases are the additions of just the past decade to the less numerous list of well-known double jeopardy decisions of past years.  Among those earlier cases are United States v. Perez, 9 Wheat. 579 (1824); Ex parte Lane, 18 Wall. 163 (1874), United States v. Ball, 163 U. S. 662 (1896); Kepner v. United States, 195 U. S. 100 (1904); Green v. United States, 355 U. S. 184 (1957); Fong Foo v. United States, 369 U. S. 141 (1962); Downum v. United States, 372 U. S. 734 (1963); United States v. Tateo, 377 U. S. 463 (1964).That the Clause is important and vital in this day is demonstrated by the host of recent cases.  That its application has not proved to be facile or routine is demonstrated by acknowledged changes in direction or in emphasis.  See, e.g., United States v. Scott, supra, overruling United States v. Jenkins, supra; and Burks v. United States, 437 U.S. at  437 U. S. 18, overruling, at least in part, certain prior cases in the area.  See also Note, 24 Minn.L.Rev. 522 (1940); Westen & Drubel, Toward a General Theory of Double Jeopardy, 1978 S.Ct.Rev. 81, 82.  Nonetheless, the following general principles emerge from the Court's double jeopardy decisions, and may be regarded as essentially settled:-- The general design of the Double Jeopardy Clause of the Fifth Amendment is that described in Green v. United States:"The constitutional prohibition against 'double jeopardy' was designed to protect an individual from being subjected to the hazards of trial and possible conviction more than once for an alleged offense. . . .  The underlying idea, one that is deeply ingrained in at least the Anglo-American system of jurisprudence, is that the State, with all its resources and power, should not be allowed to make repeated attempts to convict an individual Page 449 U. S. 128 for an alleged offense, thereby subjecting him to embarrassment, expense and ordeal and compelling him to live in a continuing state of anxiety and insecurity, as well as enhancing the possibility that, even though innocent, he may be found guilty."355 U.S. at  355 U. S. 187-188.  See also Serfass v. United States, 420 U.S. at  420 U. S. 387-388; Crist v. Bretz, 437 U.S. at  437 U. S. 35.  This concept has ancient roots centering in the common law pleas of autre fois acquit, autre fois convict, and pardon, 4 W. Blackstone, Commentaries 329-330 (1st ed. 1769), and found expression in the legal tradition of colonial America.  See Green v. United States, 355 U.S. at  355 U. S. 187; id. at  355 U. S. 200 (dissenting opinion); United States v. Wilson, 420 U.S. at  420 U. S. 339-342; United States v. Scott, 437 U.S. at  437 U. S. 87.-- The stated design, in terms of specific purpose, has been expressed in various ways.  It has been said that "a" or "the" "primary purpose" of the Clause was "to preserve the finality of judgments," Crist v. Bretz, 437 U.S. at  437 U. S. 33, or the "integrity" of judgments, United States v. Scott, 437 U.S. at  437 U. S. 92.  But it has also been said that "central to the objective of the prohibition against successive trials" is the barrier to "affording the prosecution another opportunity to supply evidence which it failed to muster in the first proceeding."  Burks v. United States, 437 U.S. at  437 U. S. 11; Swisher v. Brady, 438 U.S. at  438 U. S. 215-216.  Implicit in this is the thought that, if the Government may reprosecute, it gains an advantage from what it learns at the first trial about the strengths of the defense case and the weaknesses of its own.  See United States v. Scott, 437 U.S. at  437 U. S. 105, n. 4 (dissenting opinion); United States v. Wilson, 420 U.S. at  420 U. S. 352.Still another consideration has been noted:"Because jeopardy attaches before the judgment becomes final, the constitutional protection also embraces the defendant's 'valued right to have his trial completed by a particular tribunal.'"Arizona v. Washington, 434 Page 449 U. S. 129 U.S. at  434 U. S. 503, quoting from Wade v. Hunter, 336 U. S. 684,  336 U. S. 689 (1949).  See Swisher v. Brady, 438 U.S. at  438 U. S. 214-215; Crist v. Bretz, 437 U.S. at  437 U. S. 36.On occasion, stress has been placed upon punishment:"It is the punishment that would legally follow the second conviction which is the real danger guarded against by the Constitution."Ex parte Lange, 18 Wall. at  85 U. S. 173.-- The Court has summarized:"That guarantee [against double jeopardy] has been said to consist of three separate constitutional protections.  It protects against a second prosecution for the same offense after acquittal.  It protects against a second prosecution for the same offense after conviction.  And it protects against multiple punishments for the same offense."(Footnotes omitted.)  North Carolina v. Pearce, 395 U. S. 711,  395 U. S. 717 (1969). [Footnote 10]  See Illinois v. Vitale, 447 U.S. at  447 U. S. 415.-- An acquittal is accorded special weight.  "The constitutional protection against double jeopardy unequivocally prohibits a second trial following an acquittal," for the "public interest in the finality of criminal judgments is so strong that an acquitted defendant may not be retried even though the acquittal was based upon an egregiously erroneous foundation.'  See Fong Foo v. United States, 369 U. S. 141,  369 U. S. 143.  If the innocence of the accused has been confirmed by a final judgment, the Constitution conclusively presumes that a second trial would be unfair."  Arizona v. Washington, 434 U.S. at  434 U. S. 503.  The law "attaches particular significance to an acquittal."  United States v. Scott, 437 U.S. at  437 U. S. 91. Page 449 U. S. 130This is justified on the ground that, however mistaken the acquittal may have been, there would be an unacceptably high risk that the Government, with its superior resources, would wear down a defendant, thereby "enhancing the possibility that, even though innocent, he may be found guilty."  Green v. United States, 355 U.S. at  355 U. S. 188.  See also United States v. Martin Linen Supply Co., 430 U.S. at  430 U. S. 571,  430 U. S. 573, n. 12.  "[W]e necessarily afford absolute finality to a jury's verdict of acquittal -- no matter how erroneous its decision."  (Emphasis in original.)  Burks v. United States, 437 U.S. at  437 U. S. 16. [Footnote 11]-- The result is definitely otherwise in cases where the trial has not ended in an acquittal.  This Court has long recognized that the Government may bring a second prosecution where a mistrial has been occasioned by "manifest necessity."  United States v. Perez, 9 Wheat. at  22 U. S. 580.  See Arizona v. Washington, 434 U.S. at  434 U. S. 514-516; Illinois v. Somerville, 410 U. S. 458 (1973).  Furthermore, reprosecution of a defendant who has successfully moved for a mistrial is not barred, so long as the Government did not deliberately seek to provoke the mistrial request.  United States v. Dinitz, 424 U.S. at  424 U. S. 606-611.Similarly, where the trial has been terminated prior to a jury verdict at the defendant's request on grounds unrelated to guilt or innocence, the Government may seek appellate review of that decision even though a second trial would be necessitated by a reversal.  See United States v. Scott, 437 U.S. at  437 U. S. 98-99.  A fortiori, the Double Jeopardy Clause does not bar a Government appeal from a ruling in favor of the defendant after a guilty verdict has been entered by the trier of fact.  See United States v. Wilson, supra; United States v. Rojas, 554 F.2d 938, 941 (CA9 1977); United States v. De Garces, 518 F.2d 1156, 1159 (CA2 1975). Page 449 U. S. 131Finally, if the first trial has ended in a conviction, the double Jeopardy guarantee "imposes no limitations whatever upon the power to retry a defendant who has succeeded in getting his first conviction set aside" (emphasis in original).  North Carolina v. Pearce, 395 U.S. at  395 U. S. 720."It would be a high price indeed for society to pay were every accused granted immunity from punishment because of any defect sufficient to constitute reversible error in the proceedings leading to conviction."United States v. Tateo, 377 U.S. at  377 U. S. 466."[T]o require a criminal defendant to stand trial again after he has successfully invoked a statutory right of appeal to upset his first conviction is not an act of governmental oppression of the sort against which the Double Jeopardy Clause was intended to protect.""United States v. Scott, 437 U.S. at  437 U. S. 91.  There is, however, one exception to this rule:  the Double Jeopardy Clause prohibits retrial after a conviction has been reversed because of insufficiency of the evidence.  Burks v. United States, supra; Greene v. Massey, 437 U.S. at  437 U. S. 24."-- Where the Clause does apply, "its sweep is absolute."  Burks v. United States, 437 U.S. at  437 U. S. 11, n. 6.-- The United States "has no right of appeal in a criminal case, absent explicit statutory authority."  United States v. Scott, 437 U.S. at  437 U. S. 84-85.  But with the enactment of the first paragraph of what is now 18 U.S.C. § 3731 by Pub.L. 91-644 in 1971, 84 Stat. 1890, permitting a Government appeal in a criminal case except "where the double jeopardy clause of the United States Constitution prohibits further prosecution," the Court necessarily concluded that "Congress intended to remove all statutory barriers to Government appeals and to allow appeals whenever the Constitution would permit."  United States v. Wilson, 420 U.S. at  420 U. S. 337.  See also United States v. Scott, 437 U.S. at  437 U. S. 85. [Footnote 12] Page 449 U. S. 132IVFrom these principles, certain propositions pertinent to the present controversy emerge:A. The Double Jeopardy Clause is not a complete barrier to an appeal by the prosecution in a criminal case.  "[W]here a Government appeal presents no threat of successive prosecutions, the Double Jeopardy Clause is not offended."  United States v. Martin Linen Supply Co., 430 U.S. at  430 U. S. 569-570.  See also United States v. Wilson, 420 U.S. at  420 U. S. 342; United States v. Scott, supra.  From this it follows that the Government's taking a review of respondent's sentence does not, in itself, offend double jeopardy principles just because its success might deprive respondent of the benefit of a more lenient sentence.  Indeed, in Wilson and again in Scott the defendant had won a total victory in the trial court, for that tribunal had terminated the case in a manner that would have allowed him to go free.  The Government, nevertheless, over the constitutional challenge, was allowed to appeal.B. The double jeopardy focus, thus, is not on the appeal, but on the relief that is requested, and our task is to determine whether a criminal sentence, once pronounced, is to be accorded constitutional finality and conclusiveness similar to that which attaches to a jury's verdict of acquittal.  We conclude that neither the history of sentencing practices, nor the pertinent rulings of this Court, nor even considerations of double jeopardy policy support such an equation.As has been noted above, the Court has said that the prohibition against multiple trials is the "controlling constitutional principle."  United States v. Wilson, 420 U.S. at  420 U. S. 346; United States v. Martin Linen Supply Co., 430 U.S. at  430 U. S. 569.  But, of course, the Court's cases show that even the protection against retrial is not absolute.  It is acquittal that prevents retrial even if legal error was committed at the trial.  United States v. Ball, 163 U. S. 662 (1896).  This is why the "law attaches particular significance to an acquittal."  United Page 449 U. S. 133 States v. Scott, 437 U.S. at  437 U. S. 91.  Appeal of a sentence, therefore, would seem to be a violation of double jeopardy only if the original sentence, as pronounced, is to be treated in the same way as an acquittal is treated, and the appeal is to be treated in the same way as a retrial.  Put another way, the argument would be that, for double jeopardy finality purposes, the imposition of the sentence is an "implied acquittal" of any greater sentence.  See Van Alstyne, In Gideon's Wake:  Harsher Penalties and the "Successful" Criminal Appellant, 74 Yale L.J. 606, 634-635 (1965).We agree with the Government that this approach does not withstand analysis.  Any reliance the Court of Appeals may have placed on Kepner v. United States, 195 U. S. 100 (1904), [Footnote 13] is misplaced, for the focus of Kepner was on the undesirability of a second trial.  There are, furthermore, fundamental distinctions between a sentence and an acquittal, and to fail to recognize them is to ignore the particular significance of an acquittal.Historically, the pronouncement of sentence has never carried the finality that attaches to an acquittal.  The common law writs of autre fois acquit and autre fois convict were protections against retrial.  See United States v. Wilson, 420 U.S. at  420 U. S. 340.  Although the distinction was not of great importance early in the English common law, because nearly all felonies, to which double jeopardy principles originally were limited, were punishable by the critical sentences of death or deportation, see Comment, Statutory Implementation of Double Jeopardy Clauses:  New Life for a Moribund Constitutional Guarantee, 65 Yale L.J. 339, 342-343 (1956), it gained importance when sentences of imprisonment became common.  The trial court's increase of a sentence, so long as it took place Page 449 U. S. 134 during the same term of court, was permitted.  This practice was not thought to violate any double jeopardy principle.  See Ex parte Lange, 18 Wall. at  85 U. S. 167; id. at  85 U. S. 192-194 (dissenting opinion); 3 E. Coke, Institutes § 438 (13th ed. 1789).  See also Commonwealth v. Weymouth, 84 Mass. 144 (1861).  The common law is important in the present context, for our Double Jeopardy Clause was drafted with the common law protections in mind.  See United States v. Wilson, 420 U.S. at  420 U. S. 340-342; Green v. United States, 355 U.S. at  355 U. S. 200-201 (dissenting opinion).  This accounts for the established practice in the federal courts that the sentencing judge may recall the defendant and increase his sentence, at least (and we venture no comment as to this limitation) so long as he has not yet begun to serve that sentence.  See, e.g., United States v. DiLorenzo, 429 F.2d 216, 221 (CA2 1970), cert. denied, 402 U.S. 950 (1971); Vincent v. United States, 337 F.2d 891, 894 (CA8 1964), cert denied, 380 U.S. 988 (1965).  Thus it may be said with certainty that history demonstrates that the common law never ascribed such finality to a sentence as would prevent a legislative body from authorizing its appeal by the prosecution.  Indeed, countries that trace their legal systems to the English common law permit such appeals.  See Can.Rev.Stat. §§ 605(1)(b) and 748(b)(ii) (1970), Martin's Annual Criminal Code 523, 636 (E. Greenspan ed.1979); New Zealand Crimes Act 1961, as amended by the Crimes Amendment Act of 1966, 1 Repr.Stat.N.Z. § 383(2) (1979).  See M. Friedland, Double Jeopardy 290 (1969).C. This Court's decisions in the sentencing area clearly establish that a sentence does not have the qualities of constitutional finality that attend an acquittal.  In Bozza v. United States, 330 U. S. 160 (1947), the defendant was convicted of a crime carrying a mandatory minimum sentence of fine and imprisonment.  The trial court, however, sentenced the defendant only to imprisonment.  Later on the same day, the judge recalled the defendant and imposed both fine and imprisonment.  Page 449 U. S. 135 This Court held that there was no double jeopardy."The Constitution does not require that sentencing should be a game in which a wrong move by the judge means immunity for the prisoner."Id. at  330 U. S. 166-167.  What the judge had done "did not twice put petitioner in jeopardy for the same offense."  Id. at  330 U. S. 167.  And in North Carolina v. Pearce, 395 U. S. 711 (1969), the Court held that there was no absolute constitutional bar to the imposition of a more severe sentence on reconviction after the defendant's successful appeal of the original judgment of conviction.  The rule of Pearce, permitting an increase of sentence on retrial, is a "well-established part of our constitutional jurisprudence."  Id. at  395 U. S. 720.  See Chaffin v. Stynchcombe, 412 U.S. at  412 U. S. 24. See also Stroud v. United States, 251 U. S. 15 (1919).  If any rule of finality had applied to the pronouncement of a sentence, the original sentence in Pearce would have served as a ceiling on the one imposed at retrial. [Footnote 14]  While Pearce dealt Page 449 U. S. 136 with the imposition of a new sentence after retrial, rather than, as here, after appeal, that difference is no more than a "conceptual nicety."  North Carolina v. Pearce, 395 U.S. at  395 U. S. 722.D. The double jeopardy considerations that bar reprosecution after an acquittal do not prohibit review of a sentence.  We have noted above the basic design of the double jeopardy provision, that is, as a bar against repeated attempts to convict, with consequent subjection of the defendant to embarrassment, expense, anxiety, and insecurity, and the possibility that he may be found guilty even though innocent.  These considerations, however, have no significant application to the prosecution's statutorily granted right to review a sentence.  This limited appeal does not involve a retrial or approximate the ordeal of a trial on the basic issue of guilt or innocence.  Under § 3576, the appeal is to be taken promptly and is essentially on the record of the sentencing court.  The defendant, of course, is charged with knowledge of the statute and its appeal provisions, and has no expectation of finality in his sentence until the appeal is concluded or the time to appeal has expired.  To be sure, the appeal may prolong the period of any anxiety that may exist, but it does so only for the finite period provided by the statute.  The appeal is no more of an ordeal than any Government appeal under 18 U.S.C. § 3731 from the dismissal of an indictment or information.  The defendant's primary concern and anxiety obviously relate to the determination of innocence or guilt, and that already is behind him.  The defendant is subject to no risk of being harassed and then convicted, although innocent.  Furthermore, a sentence is characteristically determined in Page 449 U. S. 137 large part on the basis of information, such as the presentence report, developed outside the courtroom.  It is purely a judicial determination, and much that goes into it is the result of inquiry that is nonadversary in nature.E. The Double Jeopardy Clause does not provide the defendant with the right to know at any specific moment in time what the exact limit of his punishment will turn out to be.  Congress has established many types of criminal sanctions under which the defendant is unaware of the precise extent of his punishment for significant periods of time, or even for life, yet these sanctions have not been considered to be violative of the Clause.  Thus, there is no double jeopardy protection against revocation of probation and the imposition of imprisonment.  See, e.g., Thomas v. United States, 327 F.2d 795 (CA10), cert. denied, 377 U.S. 1000 (1964).  There are other situations where probation or parole may be revoked and sentence of imprisonment imposed.  See, e.g., United States v. Kuck, 573 F.2d 25 (CA10 1978); United States v. Walden, 578 F.2d 966, 972 (CA3 1978), cert. denied, 444 U.S. 849 (1979); United States v. Jones, 540 F.2d 465 (CA10 1976), cert. denied, 429 U.S. 1101 (1977); Dunn v. United States, 182 U.S.App.D.C. 261, 561 F.2d 259 (1977).  While these criminal sanctions do not involve the increase of a final sentence, and while the defendant is aware at the original sentencing that a term of imprisonment later may be imposed, the situation before us is different in no critical respect.  Respondent was similarly aware that a dangerous special offender sentence is subject to increase on appeal.  His legitimate expectations are not defeated if his sentence is increased on appeal any more than are the expectations of the defendant who is placed on parole or probation that is later revoked.All this highlights the distinction between acquittals and sentences.  North Carolina v. Pearce and Bozza v. United States demonstrate that the Double Jeopardy Clause does not require that a sentence be given a degree of finality that prevents its later increase.  Because of the critical difference between Page 449 U. S. 138 an acquittal and a sentence, the acquittal cases, such as Kepner v. United States, 195 U. S. 100 (1904), and Fong Foo v. United States, 369 U. S. 141 (1962), do not require a contrary result.VWe turn to the question whether the increase of a sentence on review under § 3576 constitutes multiple punishment in violation of the Double Jeopardy Clause.  The Court of Appeals found that it did.  604 F.2d  at 784-787.  This conclusion appears to be attributable primarily to that court's extending to an appeal this Court's dictum in United States v. Benz, 282 U. S. 304,  282 U. S. 307 (1931), to the effect that the federal practice of barring an increase in sentence by the trial court after service of the sentence has begun is constitutionally based. [Footnote 15]  The real and only issue in Benz, however, was whether the trial judge had the power to reduce a defendant's sentence after service had begun.  The Court held that the trial court had such power.  It went on to say gratuitously, however, id. at  282 U. S. 307-308, and with quotations from a textbook and from Ex parte Lange, 18 Wall. at  85 U. S. 167,  85 U. S. 173, that the trial court may not increase a sentence, even though the increase is effectuated during the same court session, if the defendant has begun service of his sentence.  But the dictum's source, Ex parte Lange, states no such principle.  In Lange, the trial court erroneously imposed both imprisonment and fine, even though it was authorized by statute to impose only one or the other of these two punishments.  Lange had paid the fine and served five days in prison.  The trial court then resentenced him to a year's imprisonment.  The fine having been paid and the defendant having suffered one of the alternative punishments, "the power of the court to punish further was gone."  Id. at  85 U. S. 176. The Court also observed that to impose Page 449 U. S. 139 a year's imprisonment (the maximum) after five days had been served was to punish twice for the same offense.  Id. at  85 U. S. 175.  The holding in Lange, and thus the dictum in Benz, are not susceptible of general application.  We confine the dictum in Benz to Lange's specific context.  Although it might be argued that the defendant perceives the length of his sentence as finally determined when he begins to serve it, and that the trial judge should be prohibited from thereafter increasing the sentence, that argument has no force where, as in the dangerous special offender statute, Congress has specifically provided that the sentence is subject to appeal.  Under such circumstances, there can be no expectation of finality in the original sentence.  See S.Rep. No. 91-617, p. 97 (1969); Dunsky, The Constitutionality of Increasing Sentences on Appellate Review, 69 J.Crim.L. & Criminology 19, 32 (1978).The guarantee against multiple punishment that has evolved in the holdings of this Court plainly is not involved in this case.  As Ex parte Lange demonstrates, a defendant may not receive a greater sentence than the legislature has authorized.  No double jeopardy problem would have been presented in Ex parte Lange if Congress had provided that the offense there was punishable by both fine and imprisonment, even though that is multiple punishment.  See Whalen v. United States, 445 U.S. at  445 U. S. 688-689; id. at  445 U. S. 697-698 (concurring opinion).  The punishment authorized by Congress under §§ 3575 and 3576 is clear and specific and, accordingly, does not violate the guarantee against multiple punishment expounded by Ex parte Lange.VIThe conclusion that § 3576 violates neither the guarantee against multiple punishment nor the guarantee against multiple trials is consistent with those opinions in which the Court has upheld the constitutionality of two-stage criminal proceedings.  Page 449 U. S. 140 See Ludwig v. Massachusetts, 427 U.S. at  427 U. S. 630-632.  See also Colten v. Kentucky, 407 U.S. at  407 U. S. 118-120. [Footnote 16]Swisher v. Brady, 438 U. S. 204 (1978), affords particular support and, indeed, precedent for the decision we reach.  That case concerned a Maryland scheme for the use of a master in a Juvenile Court proceeding.  The master, after receiving evidence, concluded that the State had failed to show beyond a reasonable doubt that the minor had committed an assault and robbery.  The master's recommendation to the Juvenile Court set forth that conclusion.  The State filed exceptions, as it was authorized to do under a procedural rule, and the minor responded with a motion to dismiss the notice of exceptions on the ground that the procedural rule, with its provision for a de novo hearing, violated the Double Jeopardy Clause.  The state courts denied relief.  On federal habeas, this Court held that the Maryland system did not violate the Clause.  Important in the decision was the fact that the system did not provide the prosecution a "second crack."  Id. at  438 U. S. 216.  The record before the master was closed "and additional evidence can be received by the Juvenile Court judge only with the consent of the minor."  Ibid.  The Court also held that there was nothing in the procedure that "unfairly subjects the defendant to the embarrassment, expense, and ordeal of a second trial. . . ."  Ibid.  The"burdens are more akin to those resulting from a judge's permissible request for post-trial Page 449 U. S. 141 briefing or argument following a bench trial than to the 'expense' of a full-blown second trial. . . ."Id. at  438 U. S. 217.  And"[t]o the extent the Juvenile Court judge makes supplemental findings . . . -- either sua sponte, in response to the State's exceptions, or in response to the juvenile's exceptions, and either on the record or on a record supplemented by evidence to which the parties raise no objection -- he does so without violating the constraints of the Double Jeopardy Clause."Id. at  438 U. S. 219.The Court in Swisher characterized the proceedings before the master and those before the Juvenile Court judge as a continuing single process and distinguished the situation in Breed v. Jones, 421 U. S. 519 (1975), where it had been held that a juvenile was placed twice in jeopardy when, after an adjudicatory finding in Juvenile Court, he was transferred to an adult criminal court and tried and convicted for the same conduct.Like the Maryland system at issue in Swisher, § 3576 does not subject a defendant to a second trial.  The Maryland system, of course, concerns a master, whereas § 3576 concerns a federal trial court.  This difference, however, is of no constitutional consequence, for the federal trial court has no power to impose a final dangerous special offender sentence that is not subject to appeal.  Section 3576, indeed, is more limited in scope than the Maryland procedure in Swisher.  The federal statute specifies that the Court of Appeals may increase the sentence only if the trial court has abused its discretion or employed unlawful procedures or made clearly erroneous findings.  The appellate court thus is empowered to correct only a legal error.  Under the Maryland procedure involved in Swisher, the judge need not find legal error on the part of the master; he is free to make a de novo determination of the facts relating to guilt or innocence.  If that is consistent with the guarantee against double jeopardy, as the Court held it was, the limited appellate review of a sentence authorized by § 3576 is necessarily constitutional.  Page 449 U. S. 142The exaltation of form over substance is to be avoided.  The Court has said that, in the double jeopardy context, it is the substance of the action that is controlling, and not the label given that action.  See United States v. Martin Linen Supply Co., 430 U.S. at  430 U. S. 571; United States v. Wilson, 420 U.S. at  420 U. S. 336.  Congress could have achieved the purpose of § 3576 by a slightly different statute whose constitutionality would be unquestionable.  Congress might have provided that a defendant found to be a dangerous special offender was to receive a specified mandatory term, but that the trial court then could recommend a lesser sentence to the court of appeals, which would be free to accept the recommendation or to reject it.  That scheme would offer no conceivable base for a double jeopardy objection.  Yet the impact on the defendant would be exactly the same as, and possibly worse than, the impact under § 3576 as written.  No double jeopardy policy is advanced by approving one of these procedures and declaring the other unconstitutional.It is perhaps worth noting in passing that § 3576 represents a considered legislative attempt to attack a specific problem in our criminal justice system, that is, the tendency on the part of some trial judges "to mete out light sentences in cases involving organized crime management personnel."  The Challenge of Crime in a Free Society, Report by the President's Commission on Law Enforcement and Administration of Justice 203 (1967).  Section 3576 was Congress' response to that plea.  See S.Rep. No. 91-617, pp. 85-87 (1969).  The statute is limited in scope, and is narrowly focused on the problem so identified.  It is not an example of "Government oppression" against which the Double Jeopardy Clause stands guard.  See United States v. Scott, 437 U.S. at  437 U. S. 99.  It has been observed elsewhere that sentencing is one of the areas of the criminal justice system most in need of reform.  See M. Frankel, Criminal Sentences:  Law Without Order (1973); P. O'Donnell, M. Churgin, & D. Curtis, Toward a Just and Page 449 U. S. 143 Effective Sentencing System (1977).  Judge Frankel himself has observed that the "basic problem" in the present system is "the unbridled power of the sentencers to be arbitrary and discriminatory."  Frankel, supra at 49.  Appellate review creates a check upon this unlimited power, and should lead to a greater degree of consistency in sentencing.We conclude that § 3576 withstands the constitutional challenge raised in the case before us.  The judgment of the Court of Appeals is reversed, and the case is remanded for further proceedings consistent with this opinion.It is so ordered
U.S. Supreme CourtUnited States v. DiFrancesco, 449 U.S. 117 (1980)United States v. DiFrancescoNo. 79-567Argued October 6, 1980Decided December 9, 1980449 U.S. 117SyllabusThe Organized Crime Control Act of 1970, 18 U.S.C. § 3576, grants the United States the right, under specified conditions, to appeal the sentence imposed upon a "dangerous special offender."  Respondent was convicted of federal racketeering offenses at a trial in Federal District Court.  He was sentenced as a dangerous special offender under 18 U.S.C. § 3575 to two 10-year prison terms, to be served concurrently with each other and with a 9-year sentence previously imposed on convictions at an unrelated federal trial.  The United States sought review of the dangerous special offender sentences under § 3576, claiming that the District Court abused its discretion in imposing sentences that amounted to additional imprisonment of respondent for only one year, in the face of the findings the court made after the dangerous special offender hearing.  The Court of Appeals dismissed the appeal on double jeopardy grounds.Held:  Section 3576 does not violate the Double Jeopardy Clause of the Fifth Amendment.  Pp.  449 U. S. 126-143.(a) Section 3576 does not violate the Double Jeopardy Clause's guarantee against multiple trials.  "[W]here a Government appeal presents no threat of successive prosecutions, the Double Jeopardy Clause is not offended."  United States v. Martin Linen Supply Co., 430 U. S. 564,  430 U. S. 569-570.  Accordingly, the Government's taking of a review of respondent's sentence does not, in itself, offend double jeopardy principles just because its success might deprive respondent of the benefit of a more lenient sentence.  Neither the history of sentencing practices, nor the pertinent rulings of this Court, nor even considerations of double jeopardy policy support the proposition that a criminal sentence, once pronounced, is to be accorded constitutional finality similar to that which attaches to a jury's verdict of acquittal.  The Double Jeopardy Clause does not provide the defendant with a right to know at any specific moment in time what the exact limit of his punishment will turn out to be.  Pp.  449 U. S. 132-138.(b) The increase of a sentence on review under § 3576 does not constitute multiple punishment in violation of the Double Jeopardy Clause.  The argument that the defendant perceives the length of his sentence as Page 449 U. S. 118 finally determined when he begins to serve it, and that the trial judge should be prohibited from thereafter increasing the sentence, has no force where, as in the dangerous special offender statute, Congress has specifically provided that the sentence is subject to appeal.  Under such circumstances, there can be no expectation of finality in the original sentence.  Pp.  449 U. S. 138-139.(c) The conclusion that § 3576 violates neither the guarantee against multiple punishment nor the guarantee against multiple trials is consistent with those opinions in which this Court has upheld the constitutionality of two-stage criminal proceedings.  Cf. Swisher v. Brady, 438 U. S. 204.  Pp.  449 U. S. 139-141.604 F.2d 769, reversed and remanded.BLACKMUN, J., delivered the opinion of the Court, in which BURGER, C.J., and STEWART, POWELL, and REHNQUIST, JJ., joined.  BRENNAN, J., filed a dissenting opinion, in which WHITE, MARSHALL, and STEVENS,, JJ., joined, post, p.  449 U. S. 143.  STEVENS, J., filed a dissenting opinion, post, p.  449 U. S. 152.