delivered the opinion of the Court.
We must here decide whether declaration of a mistrial over the defendant’s objection, because the trial court concluded that the indictment was insufficient to charge a crime, necessarily prevents a State from subsequently trying the defendant under a valid indictment. We hold that the mistrial met the “manifest necessity” requirement of our cases, since the trial court could reasonably have concluded that the “ends of public justice” would be defeated by having allowed the trial to continue. Therefore, the Double Jeopardy Clause of the Fifth Amendment, made applicable to the States through the Due Process Clause of the Fourteenth Amendment, Benton v. Maryland, 395 U. S. 784 (1969), did not bar retrial under a valid indictment.
I
On March 19, 1964, respondent was indicted by an Illinois grand jury for the crime of theft. The case was called for trial and a jury impaneled and sworn on November 1, 1965. The following day, before any evidence had been presented, the prosecuting attorney realized that the indictment was fatally deficient under Illinois law because it did not allege that respondent intended to permanently deprive the owner of his property. Under the applicable Illinois criminal statute, such intent is a necessary element of the crime of theft,1 and failure to allege intent renders the indictment insufficient to charge a crime. But under the Illinois Constitution at that time,2 an indictment was the sole means by which a crimi*460nal proceeding such as this might be commenced against a defendant. Illinois further provides that only formal defects, of which this was not one, may be cured by amendment. The combined operation of these rules of Illinois procedure and substantive law meant that the defect in the indictment was “jurisdictional”; it could not be waived by the defendant’s failure to object, and could be asserted on appeal or in a post-conviction proceeding to overturn a final judgment of conviction.
Faced with this situation, the Illinois trial court concluded that further proceedings under this defective indictment would be useless and granted the State’s motion for a mistrial. On November 3, the grand jury handed down a second indictment alleging the requisite intent. Respondent was arraigned two weeks after the first trial was aborted, raised a claim of double jeopardy which was overruled, and the second trial commenced shortly thereafter. The jury returned a verdict of guilty, sentence was imposed, and the Illinois courts upheld the conviction. Respondent then sought federal habeas corpus, alleging that the conviction constituted double jeopardy contrary to the prohibition of the Fifth and Fourteenth Amendments. The Seventh Circuit affirmed the denial of habeas corpus prior to our decision in United States v. Jorn, 400 U. S. 470 (1971). The respondent’s petition for certiorari was granted, and the case remanded for reconsideration in light of Jorn and Downum v. United States, 372 U. S. 734 (1963). On remand, the Seventh Circuit held that respondent’s petition for habeas corpus should have been granted because, although he had not been tried and acquitted as in United States v. Ball, 163 U. S. 662 (1896), and Benton v. Maryland,, 395 U. S. 784 (1969), jeopardy had attached when the jury was impaneled and sworn, and a declaration of mistrial over respondent’s objection precluded a retrial *461under a valid indictment. 447 F. 2d 733 (1971). For the reasons stated below, we reverse that judgment.
II
The fountainhead decision construing the Double Jeopardy Clause in the context of a declaration of a mistrial over a defendant’s objection is United States v. Perez, 9 Wheat. 579 (1824). Mr. Justice Story, writing for a unanimous Court, set forth the standards for determining whether a retrial, following a declaration of a mistrial over a defendant’s objection, constitutes double jeopardy within the meaning of the Fifth Amendment. In holding that the failure of the jury to agree on a verdict of either acquittal or conviction did not bar retrial of the defendant, Mr. Justice Story wrote:
“We think, that in all cases of this nature, the law has invested Courts of justice with the authority to discharge a jury from giving any verdict, whenever, in their opinion, taking all the circumstances into consideration, there is a manifest necessity for the act, or the ends of public justice would otherwise be defeated. They are to exercise a sound discretion on the subject; and it is impossible to define all the circumstances, which would render it proper to interfere. To be sure, the power ought to be used with the greatest caution, under urgent circumstances, and for very plain and obvious causes; and, in capital cases especially, Courts should be extremely careful how they interfere with any of the chances of life, in favour of the prisoner. But, after all, they have the right to order the discharge; and the security which the public have for the faithful, sound, and conscientious exercise of this discretion, rests, in this, as in other cases, upon the responsibility of the Judges, under their oaths of office.” Id., at 580.
*462This formulation, consistently adhered to by this Court in subsequent decisions, abjures the application of any mechanical formula by which to judge the propriety of declaring a mistrial in the varying and often unique situations arising during the course of a criminal trial. The broad discretion reserved to the trial judge in such circumstances has been consistently reiterated in decisions of this Court. In Wade v. Hunter, 336 U. S. 684 (1949), the Court, in reaffirming this flexible standard, wrote:
“We are asked to adopt the Cornero [v. United States, 48 F. 2d 69,] rule under which petitioner contends the absence of witnesses can never justify discontinuance of a trial. Such a rigid formula is inconsistent with the guiding principles of the Perez decision to which we adhere. Those principles command courts in considering whether a trial should be terminated without judgment to take 'all circumstances into account’ and thereby forbid the mechanical application of an abstract formula. The value of the Perez principles thus lies in their capacity for informed application under widely different circumstances without injury to defendants or to the public interest.” Id., at 691.
Similarly, in Gori v. United States, 367 U. S. 364 (1961), the Court again underscored the breadth of a trial judge’s discretion, and the reasons therefor, to declare a mistrial.
“Where, for reasons deemed compelling by the trial judge, who is best situated intelligently to make such a decision, the ends of substantial justice cannot be attained without discontinuing the trial, a mistrial may be declared without the defendant’s consent and even over his objection, and he may be retried consistently with the Fifth Amendment.” Id., at 368.
In reviewing the propriety of the trial judge’s exercise of his discretion, this Court, following the counsel of Mr. *463Justice Story, has scrutinized the action to determine whether, in the context of that particular trial, the declaration of a mistrial was dictated by “manifest necessity” or the “ends of public justice.” The interests of the public in seeing that a criminal prosecution proceed to verdict, either of acquittal or conviction, need not be forsaken by the formulation or application of rigid rules that necessarily preclude the vindication of that interest. This consideration, whether termed the “ends of public justice,” United States v. Perez, supra, at 580, or, more precisely, “the public’s interest in fair trials designed to end in just judgments,” Wade v. Hunter, supra, at 689, has not been disregarded by this Court.
In United States v. Perez, supra, and Logan v. United States, 144 U. S. 263 (1892), this Court held that “manifest necessity” justified the discharge of juries unable to reach verdicts, and, therefore, the Double Jeopardy Clause did not bar retrial. Cf. Keerl v. Montana, 213 U. S. 135 (1909); Dreyer v. Illinois, 187 U. S. 71 (1902). In Simmons v. United States, 142 U. S. 148 (1891), a trial judge dismissed the jury, over defendant’s objection, because one of the jurors had been acquainted with the defendant, and, therefore, was probably prejudiced against the Government; this Court held that the trial judge properly exercised his power “to prevent the defeat of the ends of public justice.” Id., at 154. In Thompson v. United States, 155 U. S. 271 (1894), a mistrial was declared after the trial judge learned that one of the jurors was disqualified, he having been a member of the grand jury that indicted the defendant. Similarly, in Lovato v. New Mexico, 242 U. S. 199 (1916), the defendant demurred to the indictment, his demurrer was overruled, and a jury sworn. The district attorney, realizing that the defendant had not pleaded to the indictment after the demurrer had been overruled, moved for the discharge of the jury and arraignment of the defendant for pleading; the jury *464was discharged, the defendant pleaded not guilty, the same jury was again impaneled, and a verdict of guilty rendered. In both of those cases this Court held that the Double Jeopardy Clause did not bar reprosecution.
While virtually all of the cases turn on the particular facts and thus escape meaningful categorization, see Gori v. United States, supra; Wade v. Hunter, supra, it is possible to distill from them a general approach, premised on the “public justice” policy enunciated in United States v. Perez, to situations such as that presented by this case. A trial judge properly exercises his discretion to declare a mistrial if an impartial verdict cannot be reached, or if a verdict of conviction could be reached but would have to be reversed on appeal due to an obvious procedural error in the trial. If an error would make reversal on appeal a certainty, it would not serve “the ends of public justice” to require that the Government proceed with its proof when, if it succeeded before the jury, it would automatically be stripped of that success by an appellate court. This was substantially the situation in both Thompson v. United States, supra, and Lovato v. New Mexico, supra. While the declaration of a mistrial on the basis of a rule or a defective procedure that would lend itself to prosecutorial manipulation would involve an entirely different question, cf. Downum v. United States, supra, such was not the situation in the above cases or in the instant case.
In Downum v. United States, the defendant was charged with six counts of mail theft, and forging and uttering stolen checks. A jury was selected and sworn in the morning, and instructed to return that afternoon. When the jury returned, the Government moved for the discharge of the jury on the ground that a key prosecution witness, for two of the six counts against defendant, was not present. The prosecution knew, prior to the selection and swearing of the jury, that this witness *465could not be found and had not been served with a subpoena. The trial judge discharged the jury over the defendant’s motions to dismiss two counts for failure to prosecute and to continue the other four. This Court, in reversing the convictions on the ground of double jeopardy, emphasized that “[e]ach case must turn on its facts,” 372 U. S., at 737, and held that the second prosecution constituted double jeopardy, because the absence of the witness and the reason therefor did not there justify, in terms of “manifest necessity,” the declaration of a mistrial.
In United States v. Jorn, supra, the Government called a taxpayer witness in a prosecution for willfully assisting in the preparation of fraudulent income tax returns. Prior to his testimony, defense counsel suggested he be warned of his constitutional right against compulsory self-incrimination. The trial judge warned him of his rights, and the witness stated that he was willing to testify and that the Internal Revenue Service agent who first contacted him warned him of his rights. The trial judge, however, did not believe the witness’ declaration that the IRS had so warned him, and refused to allow him to testify until after he had consulted with an attorney. After learning from the Government that the remaining four witnesses were “similarly situated,” and after surmising that they, too, had not been properly informed of their rights, the trial judge declared a mistrial to give the witnesses the opportunity to consult with attorneys. In sustaining a plea in bar of double jeopardy to an attempted second trial of the defendant, the plurality opinion of the Court, emphasizing the importance to the defendant of proceeding before the first jury sworn, concluded:
“It is apparent from the record that no consideration was given to the possibility of a trial continuance; indeed, the trial judge acted so abruptly in *466discharging the jury that, had the prosecutor been disposed to suggest a continuance, or the defendant to object to the discharge of the jury, there would have been no opportunity to do so. When one examines the circumstances surrounding the discharge of this jury, it seems abundantly apparent that the trial judge made no effort to exercise a sound discretion to assure that, taking all the circumstances into account, there was a manifest necessity for the sua sponte declaration of this mistrial. United States v. Perez, 9 Wheat., at 580. Therefore, we must conclude that in the circumstances of this case, appellee’s reprosecution would violate the double jeopardy provision of the Fifth Amendment.” 400 U. S., at 487.
III
Respondent advances two arguments to support the conclusion that the Double Jeopardy Clause precluded the second trial in the instant case. The first is that since United States v. Ball, 163 U. S. 662 (1896), held that jeopardy obtained even though the indictment upon which the defendant was first acquitted had been defective, and since Downurn v. United States, supra, held that jeopardy “attaches” when a jury has been selected and sworn, the Double Jeopardy Clause precluded the State from instituting the second proceeding that resulted in respondent’s conviction. Alternatively, respondent argues that our decision in United States v. Jorn, supra, which respondent interprets as narrowly limiting the circumstances in which a mistrial is manifestly necessary, requires affirmance. Emphasizing the “ ‘valued right to have his trial completed by a particular tribunal,’ ” United States v. Jorn, supra, at 484, quoting Wade v. Hunter, 336 U. S., at 689, respondent contends that the circumstances did not justify depriving him of that right.
*467Respondent’s first contention is precisely the type of rigid, mechanical rule which the Court had eschewed since the seminal decision in Perez. The major premise of the syllogism — that trial on a defective indictment precludes retrial — is not applicable to the instant case because it overlooks a crucial element of the Court’s reasoning in United States v. Ball, supra. There, three men were indicted and tried for murder; two were convicted by a jury and one acquitted. This Court reversed the convictions on the ground that the indictment was fatally deficient in failing to allege that the victim died within a year and a day of the assault. Ball v. United States, 140 U. S. 118 (1891). A proper indictment was returned and the Government retried all three of the original defendants; that trial resulted in the conviction of all. This Court reversed the conviction of the one defendant who originally had been acquitted, sustaining his plea of double jeopardy. But the Court was obviously and properly influenced by the fact that the first trial had proceeded to verdict. This focus of the Court is reflected in the opinion:
“[W]e are unable to resist the conclusion that a general verdict of acquittal upon the issue of not guilty to an indictment undertaking to charge murder, and not objected to before the verdict as insufficient in that respect, is a bar to a second indictment for the same killing.
“. . . [T]he accused, whether convicted or acquitted, is equally put in jeopardy at the first trial. . . .” 163 U. S., at 669 (emphasis added).
In Downum, the Court held, as respondent argues, that jeopardy “attached” when the first jury was selected and sworn. But in cases in which a mistrial has been declared prior to verdict, the conclusion that jeopardy has attached begins, rather than ends, the inquiry as to whether the Double Jeopardy Clause bars retrial. *468That, indeed, was precisely the rationale of Perez and subsequent cases. Only if jeopardy has attached is a court called upon to determine whether the declaration of a mistrial was required by “manifest necessity” or the “ends of public justice.”
We believe that in light of the State’s established rules of criminal procedure, the trial judge’s declaration of a mistrial was not an abuse of discretion. Since this Court’s decision in Benton v. Maryland, supra, federal courts will be confronted with such claims that arise in large measure from the often diverse procedural rules existing in the 50 States. Federal courts should not be quick to conclude that simply because a state procedure does not conform to the corresponding federal statute or rule, it does not serve a legitimate state policy. Last Term, recognizing this fact, we dismissed a writ of certiorari as improvidently granted in a case involving a claim of double jeopardy stemming from the dismissal of an indictment under the “rules of criminal pleading peculiar to” an individual State followed by a retrial under a proper indictment. Duncan v. Tennessee, 405 U. S. 127 (1972).
In the instant case, the trial judge terminated the proceeding because a defect was found to exist in the indictment that was, as a matter of Illinois law, not curable by amendment. The Illinois courts have held that even after a judgment of conviction has become final, the defendant may be released on habeas corpus, because the defect in the indictment deprives the trial court of “jurisdiction.” The rule prohibiting the amendment of all but formal defects in indictments is designed to implement the State’s policy of preserving the right of each defendant to insist that a criminal prosecution against him be commenced by the action of a grand jury. The trial judge was faced with a situation similar to those in Simmons, Lovato, and Thompson, in which a *469procedural defect might or would preclude the public from either obtaining an impartial verdict or keeping a verdict of conviction if its evidence persuaded the jury. If a mistrial were constitutionally unavailable in situations such as this, the State’s policy could only be implemented by conducting a second trial after verdict and reversal on appeal, thus wasting time, energy, and money for all concerned. Here, the trial judge’s action was a rational determination designed to implement a legitimate state policy, with no suggestion that the implementation of that policy in this manner could be manipulated so as to prejudice the defendant. This situation is thus unlike Downum, where the mistrial entailed not only a delay for the defendant, but also operated as a post-jeopardy continuance to allow the prosecution an opportunity to strengthen its case. Here, the delay was minimal, and' the mistrial was, under Illinois law, the only way in which a defect in the indictment could be corrected. Given the established standard of discretion set forth in. Perez, Gori, and Hunter, we cannot say that the declaration of a mistrial was not required by “manifest necessity” or the “ends of public justice.”
Our decision in Jorn, relied upon by the court below and respondent, does not support the opposite conclusion. While it is possible to excise various portions of the plurality opinion to support the result reached below, divorcing the language from the facts of the case serves only to distort its holdings. That opinion dealt with action by a trial judge that can fairly be described as erratic. The Court held that the lack of apparent harm to the defendant from the declaration of a mistrial did not itself justify the mistrial, and concluded that there was no “manifest necessity” for the mistrial, as opposed to less drastic alternatives. The Court emphasized that the absence of any manifest need for the mistrial had *470deprived the defendant of his right to proceed before the first jury, but it did not hold that that right may never be forced to yield, as in this case, to “the public's interest in fair trials designed to end in just judgments.” The Court’s opinion in Jorn is replete with approving references to Wade v. Hunter, supra, which latter case stated:
“The double-jeopardy provision of the Fifth Amendment, however, does not mean that every time a defendant is put to trial before a competent tribunal he is entitled to go free if the trial fails to end in a final judgment. Such a rule would create an insuperable obstacle to the administration of justice in many cases in which there is no semblance of the type of oppressive practices at which the double-jeopardy prohibition is aimed. There may be unforeseeable circumstances that arise during a trial making its completion impossible, such as the failure of a jury to agree on a verdict. In such event the purpose of law to protect society from those guilty of crimes frequently would be frustrated by denying courts power to put the defendant to trial again. And there have been instances where a trial judge has discovered facts during a trial which indicated that one or more members of the jury might be biased against the Government or the defendant. It is settled that the duty of the judge in this event is to discharge the jury and direct a retrial. What has been said is enough to show that a defendant’s valued right to have his trial completed by a particular tribunal must in some instances be subordinated to the public’s interest in fair trials designed to end in just judgments.” Wade v. Hunter, 336 U. S., at 688-689 (footnote omitted; emphasis added).
*471The determination by the trial court to abort a criminal proceeding where jeopardy has attached is not one to be lightly undertaken, since the interest of the defendant in having his fate determined by the jury first impaneled is itself a weighty one. United States v. Jorn, supra. Nor will the lack of demonstrable additional prejudice preclude the defendant’s invocation of the double jeopardy bar in the absence of some important countervailing interest of proper judicial administration. Ibid. But where the declaration of a mistrial implements a reasonable state policy and aborts a proceeding that at best would have produced a verdict that could have been upset at will by one of the parties, the defendant’s interest in proceeding to verdict is outweighed by the competing and equally legitimate demand for public justice. Wade v. Hunter, supra.
Reversed.
Ill. Rev. Stat., c. 38, §16-1 (d)(1) (1963).
See Constitution of Illinois, Art. II, § 8 (1967). When the State Constitution was amended in 1970, this provision was retained as the first paragraph of Art. I, § 7.