delivered the opinion of the Court.
Reviewing courts normally disregard trial errors that are harmless. This case asks us to decide whether a federal ha- *435 beas court should consider a trial error harmless when the court (1) reviews a state-court judgment from a criminal trial, (2) finds a constitutional error, and (3) is in grave doubt about whether or not that error is harmless. We recognize that this last mentioned circumstance, “grave doubt,” is unusual. Normally a record review will permit a judge to make up his or her mind about the matter. And indeed a judge has an obligation to do so. But we consider here the legal rule that governs the special circumstance in which record review leaves the conscientious judge in grave doubt about the likely effect of an error on the jury’s verdict. (By “grave doubt” we mean that, in the judge’s mind, the matter is so evenly balanced that he feels himself in virtual equipoise as to the harmlessness of the error.) We conclude that the uncertain judge should treat the error, not as if it were harmless, but as if it affected the verdict (i. e., as if it had a “substantial and injurious effect or influence in determining the jury’s verdict”).
I
Robert O’Neal filed a federal habeas corpus petition challenging his state-court convictions for murder and other crimes. The Federal District Court agreed with several of his claims of constitutional trial error. On appeal the Sixth Circuit disagreed with the District Court, with one important exception. That exception focused on possible jury “confusion” arising out of a trial court instruction about the state of mind necessary for conviction combined with a related statement by a prosecutor. The Sixth Circuit assumed, for argument’s sake, that the instruction (taken together with the prosecutor’s statement) had indeed violated the Federal Constitution by misleading the jury. Nonetheless, the court disregarded the error on the ground that it was “harmless.” O'Neal v. Morris, 3 F. 3d 143, 147 (1993).
The court’s opinion sets forth the standard normally applied by a federal habeas court in deciding whether or not this kind of constitutional “trial” error is harmless, namely,
*436
whether the error “ ‘ “had substantial and injurious effect or influence in determining the jury’s verdict.’””
Id.,
at 145 (quoting
Brecht
v.
Abrahamson,
This Court granted certiorari to decide what the law requires in such circumstances. We repeat our conclusion: When a federal judge in a habeas proceeding is in grave doubt about whether a trial error of federal law had “substantial and injurious effect or influence in determining the jury’s verdict,” that error is not harmless. And, the petitioner must win.
II
As an initial matter, we note that we deliberately phrase the issue in this case in terms of a judge’s grave doubt, instead of in terms of “burden of proof.” The case before us does not involve a judge who shifts a “burden” to help control the presentation of evidence at a trial, but rather involves a judge who applies a legal standard (harmlessness) to a record that the presentation of evidence is no longer likely to affect. In such a case, we think it conceptually clearer for the judge to ask directly, “Do I, the judge, think that the error substantially influenced the jury’s decision?” than for the judge to try to put the same question in terms *437 of proof burdens (e. g., “Do I believe the party has borne its burden of showing . . . ?”). As Chief Justice Traynor said:
“Whether or not counsel are helpful, it is still the responsibility of the . . . court, once it concludes there was error, to determine whether the error affected the judgment. It must do so without benefit of such aids as presumptions or allocated burdens of proof that expedite fact-finding at the trial.” R. Traynor, The Riddle of Harmless Error 26 (1970) (hereinafter Traynor).
The case may sometimes arise, however, where the record is so evenly balanced that a conscientious judge is in grave doubt as to the harmlessness of an error. See id., at 22-23. This is the narrow circumstance we address here.
Ill
Our legal conclusion — that in cases of grave doubt as to harmlessness the petitioner must win — rests upon three considerations. First, precedent supports our conclusion. As this Court has stated, “the original common-law harmless-error rule put the burden on the beneficiary of the error [here, the State]... to prove that there was no injury ....”
Chapman
v.
California,
“If, when all is said and done, the [court’s] conviction is sure that the error did not influence the jury, or had but very slight effect, the verdict and the judgment should stand .... But if one cannot say, with fair assurance, after pondering all that happened without stripping the erroneous action from the whole, that the judgment was not substantially swayed by the error, it is impossible to *438 conclude that substantial rights were not affected. The inquiry cannot be merely whether there was enough to support the result, apart from the phase affected by the error. It is rather, even so, whether the error itself had substantial influence. If so, or if one is left in grave doubt, the conviction cannot stand.”328 U. S., at 764-765 (emphasis added).
Id.,
at 776 (holding that error is not harmless if it had “substantial and injurious effect or influence” upon the jury). That is to say, if a judge has “grave doubt” about whether an error affected a jury in this way, the judge must treat the error as if it did so. See also
United States
v.
Olano,
When this Court considered the same question in the context of direct review of a
constitutional
trial error, it applied the same rule. See
Chapman,
We must concede that in
Brecht
v.
Abrahamson
this Court, in the course of holding that the more lenient
Kot-teakos
harmless-error standard, rather than the stricter
Chapman
standard, normally governs cases of habeas review of constitutional trial errors, stated that habeas petitioners “are not entitled to habeas relief based on trial error unless
they
can establish that it resulted in ‘actual prejudice.’”
Brecht,
We further acknowledge that this Court, in
Palmer
v.
Hoffman,
“He who seeks to have a judgment set aside because of an erroneous ruling carries the burden of showing that prejudice resulted.” Id., at 116.
But this
pre-Kotteakos
language, in context, referred to what the preceding sentence in
Palmer
described as “[m]ere ‘technical errors.’”
“ ‘upon the party seeking a new trial the burden of showing that any technical errors that he may complain of have affected his substantial rights.’” Kotteakos,328 U. S., at 760 (quoting H. R. Rep. No. 913, 65th Cong., 3d Sess., 1 (1919)).
The Report, however, (as Kotteakos immediately points out) goes on to say that if the error is not “technical,” if, instead,
*440 “ ‘the error is of such a character that its natural effect is to prejudice a litigant’s substantial rights, [then] the burden of sustaining a verdict will, notwithstanding this legislation rest upon the one who claims under it.’” H. R. Rep. No. 913, swpra, at 1.
The “grave doubt” language of
Kotteakos
itself makes clear that important trial errors, including any “constitutional violation, . . . fall in” this last mentioned category, and not “in the ‘technical’ category” that the House Report described.
Brecht, supra,
at 641 (Stevens, J., concurring); see
Bruno
v.
United States,
We also have examined the precedent upon which the State relies to support its view that appellants bear a “burden” of showing “prejudice” in civil cases. See,
e. g., Erskine
v.
Consolidated Rail Corp.,
One problem with this argument lies in its failure to take into account the stakes involved in a habeas proceeding. Unlike the civil cases cited by the State, the errors being considered by a habeas court occurred in a criminal proceeding, and therefore, although habeas is a civil proceeding, someone’s custody, rather than mere civil liability, is at stake. And, as we have explained, when reviewing errors from a criminal proceeding, this Court has consistently held that, if the harmlessness of the error is in grave doubt, relief must be granted. We hold the same here.
*441
Moreover, precedent suggests that civil and criminal harmless-error standards do not differ in their treatment of grave doubt as to the harmlessness of errors affecting substantial rights. In
Kotteakos,
the Court interpreted the then-existing harmless-error statute, 28 U. S. C. §391, now codified with minor change at 28 U. S. C. § 2111. See
Kotteakos,
Second, our conclusion is consistent with the basic purposes underlying the writ of habeas corpus. As we have said, we are dealing here with an error of constitutional dimension — the sort that risks an unreliable trial outcome and the consequent conviction of an innocent person. See
Brecht,
*443 We concede that this opposite rule (denying the writ) would help protect the State’s interest in the finality of its judgments and would promote federal-state comity. It would avoid retrials, some of which, held so late in the day, may lead to freedom for some petitioners whose initial convictions were in fact unaffected by the errors that took place at their initial trials. The State’s interest in avoiding retrial of this latter category of individuals is legitimate and important. But this interest is somewhat diminished by the legal circumstance that the State normally bears responsibility for the error that infected the initial trial. And, if one assumes (1) that in cases of grave doubt, the error is at least as likely to have been harmful in fact as not, and (2) that retrial will often (or even sometimes) lead to reconviction, then that state interest is further diminished by a factual circumstance: the number of acquittals wrongly caused by grant of the writ and delayed retrial (the most serious harm affecting the State’s legitimate interests) will be small when compared with the number of persons whom this opposite rule (denying the writ) would wrongly imprison or execute. On balance, we must doubt that the law of habeas corpus would hold many people in prison “in violation of the Constitution,” for fear that otherwise a smaller number, not so held, may eventually go free.
Third, our rule has certain administrative virtues. It is consistent with the way that courts have long treated important trial errors. See,
e. g., Olano, supra; Lane, supra; Chapman,
IV
The State makes one additional argument. It points to language in the habeas corpus statute that says the federal courts
“shall entertain an application for a writ of habeas corpus . . . only on the ground that [a petitioner] is in custody in violation of the Constitution or laws or treaties of the United States.” 28 U. S. C. § 2254(a).
See § 2241(c)(3). If a “violation of the Constitution” is harmless, the State adds, then there is no causal connection between “violation” and “custody,” and the prisoner is not “in custody in violation of the Constitution.” And, by analogy to tort law, the State contends that, because the habeas petitioner is in the position of plaintiff, he must prove this causal connection. Whatever force there may be to this argument is countered by the equally persuasive analogy to affirmative defenses, on which the party in the position of defendant (here the State) bears the risk of equipoise. And, to read the statute as the State suggests would run counter to the principle of
Kotteakos
that when an error’s natural effect is to prejudice substantial rights and the court is in grave doubt about the harmlessness of that error, the error must be treated as if it had a “substantial and injurious effect” on the verdict. See
Kotteakos,
We do not see what in the language of the statute tells a court that it should treat a violation as harmless when it is in grave doubt about its harmlessness. One might as easily infer the opposite — that the statute leaves the matter of harmlessness as a kind of affirmative defense — from the absence, in the Habeas Corpus Rules’ form petition, of any space for a “lack of harmlessness” allegation. See 28 U. S. C. § 2254 Rule 2(c) (providing in part that a habeas petition “shall be in substantially the form annexed to these
*445
rules”). Or, one might as easily infer neutrality on the point from the statute’s command that the court dispose of the petition “as law and justice require.” 28 U. S. C. §2243. Ultimately, we find no significant support for either side in any of this language. When faced with such gaps in the ha-beas statute, we have “look[ed] first to the considerations underlying our habeas jurisprudence, and then determined] whether the proposed rule would advance or inhibit these considerations by weighing the marginal costs and benefits of its application on collateral review.”
Brecht,
V
For these reasons, the judgment of the Court of Appeals is vacated, and the case is remanded for further proceedings consistent with this opinion.
It is so. ordered.
dissenting.
In my view, a federal habeas court may not upset the results of a criminal trial unless it concludes both that the trial was marred by a violation of the Constitution or a federal statute and that this error was harmful. Because the Court concludes otherwise, I respectfully dissent.
I
Though the majority begins with an examination of precedent construing the federal harmless-error statute, 28 U. S. C. §2111, the proper place to begin is with the statute governing habeas relief for prisoners in state custody. After all, the petitioner does not seek relief under the harmless-error statute.
*446 Where a state prisoner is concerned, a writ of habeas corpus may issue only when that prisoner is “in custody in violation of the Constitution or laws or treaties of the United States.” 28 U. S. C. §§ 2241(c)(3), 2254(a). It is not enough that the habeas petitioner is in custody and that some violation of the Constitution or a federal statute occurred at trial; as amicus curiae the Solicitor General correctly argues, the statute requires a causal link between the violation and the custody. Quite obviously, a habeas petitioner who proves that a trivial (“harmless”) error occurred at trial will not secure habeas relief because such an error could not be said to have been a cause of the custody. Notwithstanding the error, the petitioner would have been in custody lawfully and thus relief is unwarranted. Even the majority implicitly agrees that causation is necessary, for otherwise it would have no need to discuss harmful errors as opposed to mere errors.
The habeas petitioner comes to federal court as a plaintiff. Because the plaintiff “seeks to change the present state of affairs,” he “naturally should be expected to bear the risk of failure of proof or persuasion.” 2 J. Strong, McCormick on Evidence § 337, p. 428 (4th ed. 1992). Part of that burden is the requirement that the plaintiff show that the defendant’s actions caused harm. In other areas of the law, the plaintiff almost invariably bears the burden of persuasion with respect to whether the defendant’s actions caused harm. See,
e. g., Wards Cove Packing Co.
v. Atonio,
Requiring the habeas petitioner to bear the risk of non-persuasion not only accords with the usual rules of litigation, but also is compelled by what we have said about the nature of habeas relief. “When the process of direct review . . . comes to an end, a presumption of finality and legality attaches to the conviction and sentence.”
Barefoot
v.
Estelle,
We have ample cause to be wary of the writ. Our criminal law does not routinely punish the innocent. Instead, our Constitution requires proof of guilt beyond a reasonable doubt. See
In re Winship,
Our habeas jurisprudence has also been informed by a proper recognition of the affront to a State when federal
*448
courts conduct habeas review. Habeas review “‘disturbs the State’s significant interest, in repose for concluded litigation, denies society the right to punish some admitted offenders, and intrudes on state sovereignty to a degree matched by few exercises of federal judicial authority.’ ”
Duckworth
v.
Eagan,
Our “harmless-error” inquiry in the habeas context concerns whether an error “ ‘had substantial and injurious effect or influence in determining the jury’s verdict.’”
Brecht, supra,
at 627 (quoting
Kotteakos
v.
United States,
II
The Court derives its contrary rule from cases construing the harmless-error statute, the purposes underlying the writ of habeas corpus, and the virtue of administrative consistency that stems from following established precedent. The Court’s analysis is unpersuasive.
A
The Court begins by examining harmless-error practice in the context of direct criminal appeals. I do not quarrel with the majority’s conclusion that once an error has been shown on direct appeal, the government must demonstrate that it was harmless if the conviction is to stand. See
ante,
at 437-438 (citing
Kotteakos, supra,
at 764-765, 776;
Chapman
v.
California,
To be sure, we have borrowed the applicable standard for judging harmlessness in habeas from cases interpreting the federal harmless-error statute. See,
e. g., Brecht, supra,
at 631. Applying harmless-error analysis makes sense, because a trivial error could not be said to cause custody and thus warrant habeas relief. But the harmless-error statute and rules do not apply of their own force in the habeas cases, and so the harmless-error precedents relied upon by the majority are certainly not dispositive. Indeed,
Brecht
itself— despite adopting the
standard
for harmlessness set out in
Kotteakos
— departed from
Kotteakos
by placing the
burden
upon the habeas petitioner to “establish” that this standard has been met. See
If we
are
to look at cases examining the harmless-error statute, I would think that civil cases would be of greater relevance. As the Court admits, habeas is a civil proceeding. See
ante,
at 440 (citing
Browder
v.
Director, Dept. of Corrections of Ill.,
The Court concludes that Palmer and these cases may be disregarded because the federal harmless-error statute, 28 U. S. C. §2111, makes no distinction between civil and criminal cases; since the rule in the criminal context places the burden of persuasion on the government, the Court decides that the same should be true in the civil context. Ante, at 441-442. But the majority’s syllogism could just as easily be turned against the result it reaches. Authority in the civil context assigns the risk of nonpersuasion to the party alleging error, and since the statute draws no distinction between civil and criminal cases, we might just as easily conclude that the civil rule should be followed in the criminal context. The Court’s reasoning yields no determinate answer.
As indicated above, however, the harmless-error provisions do not actually apply in habeas cases anyway. We have no occasion to harmonize the harmless-error cases by overruling Palmer and by rejecting the practice that prevails in the majority of the Courts of Appeals that have considered the issue, as the Court does today.
B
The Court’s second claim is that its “conclusion is consistent with the basic purposes underlying the writ of habeas corpus.” Ante, at 442. As part of its argument, the Court *451 lays claim to the moral high ground: “[W]e are dealing here with an error of constitutional dimension — the sort that risks an unreliable trial outcome and the consequent conviction of an innocent person.” Ibid. The Court suggests that when there is a grave doubt about the harmfulness of an error, “a legal rule requiring issuance of the writ will, at least often, avoid a grievous wrong — holding a person ‘in custody in violation of the Constitution ... of the United States.’” Ibid. (quoting 28 U. S. C. §§ 2241(c)(3), 2254(a)).
The Court concedes that there are other interests at stake — a State’s interest in the finality of its judgments and the promotion of federal-state comity, see ante, at 443 — but goes on to set these principles aside. The Court concludes that the State’s interest in finality, while “legitimate and important,” ibid., is diminished by the fact that “the number of acquittals wrongly caused by grant of the writ and delayed retrial.. . will be small when compared with the number of persons whom [the] opposite rule . . . would wrongly imprison or execute,” ibid.
Despite its rhetoric, the Court itself is merely balancing the costs and benefits associated with disturbing judgments when a court is in grave doubt about harm. The Court decides that the possibility of unlawful custody should lead to the adoption of its grave doubt rule. But because the Court draws the line at “grave doubt” rather than “significant doubt” or “any doubt,” it is not willing to go as far as it must in order to ensure that no one is unlawfully imprisoned. Thus, under the majority’s assumptions, even its own rule will guarantee that “many, in fact, will be held in unlawful custody.” Ante, at 442.
It is important to recognize, moreover, that when the Court discusses erroneous imprisonments and executions, it is not addressing questions of innocence or guilt. The standard for judging harmlessness in habeas cases certainly does not turn on the innocence of the habeas petitioner. In fact, the Court’s rule applies only when the habeas court can *452 not make up its mind about whether a jury would have entertained any reasonable doubt about the defendant’s guilt. Though the majority seems to suggest otherwise, it certainly will not be true that in half of such cases, the State will have unjustly imprisoned an innocent person.
C
Citing
Kotteakos, Chapman,
and other cases, the Court concludes that its rule will be easier to administer because it is consistent with the way courts have treated grave doubts about harm.
Ante,
at 443. As indicated above,
Palmer
and the majority view in the Courts of Appeals provide an equally attractive rule that is consistent with longstanding practice. As for the Court’s assertion that its rule eliminates “the need for judges to read lengthy records to determine prejudice in every habeas case,”
ante,
at 443, I thought it settled that “it is the duty of a reviewing court to consider the trial record as a whole” when conducting a harmless-error analysis,
United States
v.
Hasting,
Ill
Fortunately, the rule announced today will affect only a minuscule fraction of cases. Even when there is a close question about whether an error was harmful, the conscientious judge ordinarily should make a ruling as to harm. The Court’s rule is not a means for judges to escape difficult decisions; it applies only in that “special circumstance” in which *453 a judge, after a thorough review of the record, remains in equipoise. See ante, at 435.
The rule has such limited application that it most likely will have no effect on this case. The majority suggests that O’Neal “might have lost in the Court of Appeals, not because the judges concluded that [any supposed] error
was
harmless, but because the record of the trial left them in grave doubt about the effect of the error.”
Ante,
at 436. The Sixth Circuit did observe that “[t]he habeas petitioner bears the burden of establishing... prejudice.”
O’Neal
v.
Morris,
Though the question that the Court decides today will have very limited application, I believe that the Court gives the wrong answer to that question.
Accordingly, I respectfully dissent.
