Justice Blackmun
delivered the opinion of the Court.
Petitioner seeks review of a decision of Maryland’s highest court which construes that State’s capital sentencing scheme in a manner that preserves its constitutionality but which may not have been evident at all to the jury charged with the sentencing function in this case. Because, we have no reason to believe that the jury also arrived at this “saving” construction, we must vacate the sentence of death and remand the case for resentencing.
I
Petitioner Ralph Mills was tried by a state-court jury and convicted of the first-degree murder of his cellmate in the Maryland Correctional Institution in Hagerstown. The jury found that petitioner repeatedly had stabbed his victim with a “shank” or homemade knife. In the sentencing phase of the trial, the same jury found that the State had established the one statutory aggravating circumstance it propounded, namely, that petitioner “committed the murder at a time when he was confined in a correctional institution.” App. 99. Defense counsel sought to persuade the jury of the presence of certain mitigating circumstances, in particular, petitioner’s relative youth, his mental infirmity, his lack of future dangerousness, and the State’s failure to make any meaningful attempt to rehabilitate petitioner while he was incarcerated. Id., at 89-93. On the verdict form provided by the trial court pursuant to the then-existing, but since rescinded, Maryland Rule of Procedure 772A, the jury marked “no” beside each referenced mitigating circumstance and returned a sentence of death.
Petitioner challenged his conviction and sentence on various grounds, including an argument that the Maryland capital-punishment statute, Md. Ann. Code, Art. 27, §413 (1987), as applied to him, was unconstitutionally mandatory. Petitioner construed the statute, as explained to the jury by the court’s instructions and as implemented by the verdict form, to require the imposition of the death sentence if the jury unanimously found an aggravating circumstance, but could not agree unanimously as to the existence of any particular mitigating circumstance. According to petitioner’s view, even if some or all of the jurors were to believe some mitigating circumstance or circumstances were present, unless they could unanimously agree on the existence of the same mitigating factor, the sentence necessarily would be death.
The Maryland Court of Appeals concluded that the imposition of petitioner’s death sentence was constitutionally sound. 310 Md. 33, 527 A. 2d 3 (1987). The court did not dispute that if the statute and form were read as petitioner suggested, jurors would be improperly prevented from giving due consideration to mitigating evidence. The court, however, interpreted the statute differently and held that the requirement of unanimity applied to jury determinations of all critical issues including the acceptance or rejection of mitigating circumstances, observing that the verdict form was to be regarded as requiring the jury to agree unanimously in order to mark “no” with respect to the existence of each mitigating circumstance, and that the trial judge’s instructions stressed the need for unanimity on all issues presented. In the absence of unanimity on the ultimate question of what sentence should be imposed, the statute required the imposition of life imprisonment. See §413(k)(2). Thus, in the court’s view, “[a]s long as one juror believes that there exists a mitigating factor, and that this factor is not outweighed by the aggravating circumstances, and if such juror continues to adhere to his or her position, the sentence will not be death under the statutory scheme.” 310 Md., at 54, 527 A. 2d, at 13.
The Court of Appeals recognized, however, that the statute did not fully provide what was to transpire when unanimity was lacking at various stages of the sentencing deliberation. Concluding that the state legislature did not intend that the jury should deadlock and impose a life sentence whenever it could not agree unanimously to accept or reject a particular mitigating circumstance, and pursuant to its statutory authority to fill gaps in the sentencing process, see § 413(Z), the Court of Appeals instructed that the jury should proceed to the balancing stage, leaving its answer to that circumstance blank. The court directed that each juror weigh the mitigating circumstances he or she found to be established and balance them against the aggravating circumstances unanimously found by the jury. 310 Md., at 66-68, 527 A. 2d, at 19-20.
The dissenting judge sharply disagreed with the majority’s view that the state legislature intended to make the rejection of a mitigating circumstance the kind of ultimate issue that requires unanimity. He observed that the law generally requires unanimity only for verdicts, not for an alternative “predicate or historic fact” in support of the verdict. Id., at 95, 527 A. 2d, at 33. The dissent also concluded that it was probable, or at least reasonably possible, that the jury understood that a “no” answer on the verdict form represented a failure to find unanimously the existence of the circumstance, rather than a unanimous determination that the circumstance did not exist. Id., at 92-95, 527 A. 2d, at 32-33.
Because of the importance of the issue in Maryland’s capital-punishment scheme, we granted certiorari. 484 U. S. 975 (1987).
II
Petitioner’s argument is straightforward, and well illustrated by a hypothetical situation he contends is possible under the Maryland capital sentencing scheme:
“If eleven jurors agree that there are six mitigating circumstances, the result is that no mitigating circumstance is found. Consequently, there is nothing to weigh against any aggravating circumstance found and the judgment is death even though eleven jurors think the death penalty wholly inappropriate.” Brief for Petitioner 11.
The dissent below postulated a situation just as intuitively disturbing: All 12 jurors might agree that some mitigating circumstances were present, and even that those mitigating circumstances were significant enough to outweigh any aggravating circumstance found to exist. But unless all 12 could agree that the same mitigating circumstance was present, they would never be permitted to engage in the weighing process or any deliberation on the appropriateness of the death penalty. 310 Md., at 79-81, 527 A. 2d, at 25-26.
Although jury discretion must be guided appropriately by objective standards, see Godfrey v. Georgia, 446 U. S. 420, 428 (1980) (plurality opinion), it would certainly be the height of arbitrariness to allow or require the imposition of the death penalty under the circumstances so postulated by petitioner or the dissent. It is beyond dispute that in a capital case “‘the sentencer [may] not be precluded from considering, as a mitigating factor, any aspect of a defendant’s character or record and any of the circumstances of the offense that the defendant proffers as a basis for a sentence less than death.’” Eddings v. Oklahoma, 455 U. S. 104, 110 (1982), quoting Lockett v. Ohio, 438 U. S. 586, 604 (1978) (plurality opinion) (emphasis in original). See Skipper v. South Carolina, 476 U. S. 1, 4 (1986). The corollary that “the sentencer may not refuse to consider or be precluded from considering ‘any relevant mitigating evidence’” is equally “well established.” Ibid, (emphasis added), quoting Eddings, 455 U. S., at 114.
Under Maryland’s sentencing scheme, if the sentencer finds that any mitigating circumstance or circumstances have been proved to exist, it then proceeds to decide whether those mitigating circumstances outweigh the aggravating circumstances and sentences the defendant accordingly. § 413(h). But if petitioner is correct, a jury that does not unanimously agree on the existence of any mitigating circumstance may not give mitigating evidence any effect whatsoever, and must impose the sentence of death. See 310 Md., at 67, 527 A. 2d, at 19. Under our decisions, it is not relevant whether the barrier to the sentencer’s consideration of all mitigating evidence is interposed by statute, Lockett v. Ohio, supra; Hitchcock v. Dugger, 481 U. S. 393 (1987); by the sentencing court, Eddings v. Oklahoma, supra; or by an evidentiary ruling, Skipper v. South Carolina, supra. The same must be true with respect to a single juror’s holdout vote against finding the presence of a mitigating circumstance. Whatever the cause, if petitioner’s interpretation of the sentencing process is correct, the conclusion would necessarily be the same: “Because the [sentencer’s] failure to consider all of the mitigating evidence risks erroneous imposition of the death sentence, in plain violation of Lockett, it is our duty to remand this case for resentencing.” Eddings v. Oklahoma, 455 U. S., at 117, n. (O’Connor, J., concurring).
Ill
A
The critical question, then, is whether petitioner’s interpretation of the sentencing process is one a reasonable jury could have drawn from the instructions given by the trial judge and from the verdict form employed in this case. See Francis v. Franklin, 471 U. S. 307, 315-316 (1985) (“The question ... is not what the State Supreme Court declares the meaning of the charge to be, but rather what a reasonable juror could have understood the charge as meaning”), citing Sandstrom v. Montana, 442 U. S. 510, 516-517 (1979). Accord, California v. Brown, 479 U. S. 538 (1987). If the jury understood the verdict form as the Court of Appeals asserted it should have, then every time it marked “no” beside a mitigating circumstance it indicated its unanimous. conclusion that petitioner had not proved the relevant facts by a preponderance of the evidence, and thus the court properly upheld the judgment. On the other hand, if the jury understood that it should mark “no” when it failed to agree unanimously that a mitigating circumstance existed, then some jurors were prevented from considering “factors which may call for a less severe penalty,” Lockett v. Ohio, 438 U. S., at 605, and petitioner’s sentence cannot stand.
With respect to findings of guilt on criminal charges, the Court consistently has followed the rule that the jury’s verdict must be set aside if it could be supported on one ground but not on another, and the reviewing court was uncertain which of the two grounds was relied upon by the jury in reaching the verdict. See, e. g., Yates v. United States, 354 U. S. 298, 312 (1957); Stromberg v. California, 283 U. S. 359, 367-368 (1931). In reviewing death sentences, the Court has demanded even greater certainty that the jury’s conclusions rested on proper grounds. See, e. g., Lockett v. Ohio, 438 U. S., at 605 (“[T]he risk that the death penalty will be imposed in spite of factors which may call for a less severe penalty ... is unacceptable and incompatible with the commands of the Eighth and Fourteenth Amendments”); Andres v. United States, 333 U. S. 740, 752 (1948) (“That reasonable men might derive a meaning from the instructions given other than the proper meaning of § 567 is probable. In death cases doubts such as those presented here should be resolved in favor of the accused”); accord, Zant v. Stephens, 462 U. S. 862, 884-885 (1983). Unless we can rule out the substantial possibility that the jury may have rested its verdict on the “improper” ground, we must remand for resentencing.
B
While conceding that the Court of Appeals’ construction of the jury instructions and verdict form is plausible, we cannot conclude, with any degree of certainty, that the jury did not adopt petitioner’s interpretation of the jury instructions and verdict form. At the conclusion of the sentencing phase, the judge distributed copies of the form to the jurors. (This form is reproduced in its entirety, with the answers given, in the Appendix to this opinion.) After reading aloud the instruction part of the form’s Section I and stressing the unanimity requirement, the judge explained: “[Y]ou must consider whether the aggravating circumstance number two has been proven beyond a reasonable doubt. If you unanimously conclude that it has been so proven, you should answer that, question yes. If you are not so satisfied, then of course you must answer no.” App. 70 (emphasis added). We find it difficult to read into that statement a requirement that the “no” answer, like the “yes” answer, must be unanimous. Indeed, the verdict form establishes at least a rough equivalence between the lack of unanimity to write “yes,” and writing “no”: the jury learns from the form that its failure to write “yes” beside any aggravating circumstance leads to the imposition of a life sentence, the same result that obtains if the jury answers “no” for every aggravating circumstance.
The judge then moved on to Section II of the form, which addresses the jury’s determination of which, if any, mitigating circumstances exist. The language at the beginning of that section is identical to that at the beginning of Section I, except that the standard of proof is by a 'preponderance of the evidence rather than beyond a reasonable , doubt, see Appendix to this opinion, post, at 387, and we présume that, unless instructed to the contrary, the jury would read similar language throughout the form consistently. The jury was instructed to mark each answer “yes” or- “no.” Although it was clear that the jury could not mark'“yes” in any box without unanimity, nothing the judge said dispelled the probable inference that “no” is the opposite of “yes,” and therefore the appropriate answer to reflect an inability to answer a question in the affirmative. Nothing in the verdict form or the judge’s instructions even arguably is construable as suggesting the jury could leave an answer blank and proceed to the next stage in its deliberations.
The only place on the form where the jury had an opportunity to write anything more than “yes” or “no” was with respect to mitigating circumstance number eight, see Appendix to this opinion, post, at 388, which permits the jury to recognize as mitigating anything, in addition to the enumerated mitigating factors, that petitioner offered as a basis for a sentence less than death. The judge explained to the jury that if it found any such “other” mitigating circumstances, it must list them in the space provided, and “[i]f you find no other mitigating circumstance then you make no entry upon those lines under number eight.” App. 73. No instruction was given indicating what the jury should do if some but not all of the jurors were willing to recognize something about petitioner, his background, or the circumstances of the crime, as a mitigating factor.
Ordinarily, a Maryland jury reaches the balancing stage of the deliberation process any time it unanimously finds at least one mitigating circumstance, or, under the interpretation adopted by the Court of Appeals in this case, any time the jury does not unanimously reject all mitigating circumstances. Had the jurors that sentenced petitioner reached Section III, they would have found that even if they had read the verdict form as the Court of Appeals suggests they could have, and marked “yes” or “no” only on the basis of unanimity as to either, they were not free at this point to consider all relevant evidence in mitigation as they balanced aggravating and mitigating circumstances. Section III instructed the jury to weigh only those mitigating circumstances marked “yes” in Section II. Any mitigating circumstance not so marked, even if not unanimously rejected, could not be considered by any juror. A jury following the instructions set out in the verdict form could be “precluded from considering, as a mitigating factor, [an] aspect of a defendant’s character or record [or a] circumstance] of the offense that the defendant proffer[ed] as a basis for a sentence less than death,” Skipper v. South Carolina, 476 U. S., at 4, if even a single juror adhered to the view that such a factor should not be so considered.
c
There is, of course, no extrinsic evidence of what the jury in this case actually thought. We have before us only the verdict form and the judge’s instructions. Our reading of those parts of the record leads us to conclude that there is at least a substantial risk that the jury was misinformed. The dissenting judge below was astounded by the majority’s reading of the statute and verdict form, which, he said, “appears out of the blue after nearly ten years of extensive litigation involving this statute.” 310 Md., at 94, 527 A. 2d, at 33. Looking to the only evidence of jury interpretation available, the dissent noted that on 25 sentencing forms completed in capital cases in which the death penalty was imposed, no answer as to the existence of mitigating circumstances was ever left blank. Id., at 94, n. 9, 527 A. 2d, at 33, n. 9.
One additional bit of evidence about the natural interpretation of the form has become available since this case was decided below on June 25, 1987. On an emergency basis, the Court of Appeals promulgated a new Findings and Sentencing Determination form. See Md. Rule Proc. 4-343(e) (amended July 27, 1987, effective Aug. 17, 1987). The new form expressly incorporates the unanimity requirement as to both accepting and rejecting aggravating circumstances. More significantly, however, the section concerning mitigating circumstances is completely rewritten and changed. Now, under each statutory mitigating circumstance, the jury is asked to choose from among three options:
“(Mark only one)
- (a) We unanimously find by a preponderance of the evidence that the above circumstance exists.
-(b) We unanimously find by a preponderance of the evidence that the above circumstance does not exist.
- (c) After a reasonable period of deliberation, one or more of us, but fewer than all 12, find by a preponder-anee of the evidence that the above circumstance exists.” Md. Ann. Code, Md. Rules, Vol. 1 (1988), pp. 494-497.
As before, the new verdict form also provides the jury the opportunity to articulate “additional mitigating circumstances.” The new form, however, unlike the one used in petitioner’s case, explicitly directs the jury to articulate any such “additional” circumstances that the jurors unanimously agree exist, and any found by “[o]ne or more . . . , but fewer than all 12” of the jurors. Id., at 497.
With respect to the consideration of mitigating evidence during the weighing and balancing process, the new verdict form instructs jurors as follows:
“(If the jury unanimously determines in Section III that no mitigating circumstances exist, do not complete Section IV. Proceed to Section V and enter ‘Death.’ If the jury or any juror determines that one or more mitigating circumstances exist, complete Section IV.)” Ibid. (emphasis added).
Section IV now reflects the requirement that jurors not be prevented from considering all evidence in mitigation:
“Each individual juror shall weigh the aggravating circumstances found unanimously to exist against any mitigating circumstances found unanimously to exist, as well as against any mitigating circumstances found by that individual juror to exist.” Ibid, (emphasis added).
Although we are hesitant to infer too much about the prior verdict form from the Court of Appeals’ well-meant efforts to remove ambiguity from the State’s capital sentencing scheme, we cannot avoid noticing these significant changes effected in instructions to the jury. We can and do infer from these changes at least some concern on the part of that court that juries could misunderstand the previous instructions as to unanimity and the consideration of mitigating evidence by individual jurors. We also note, for what it may be worth, that in two cases tried since a Maryland jury has been given the option of reporting nonunanimous votes, the jury has done so.
No one on this Court was a member of the jury that sentenced Ralph Mills, or of any similarly instructed jury in Maryland. We cannot say with any degree of confidence which interpretation Mills’ jury adopted. But common sense and what little extrinsic evidence we possess suggest that juries do not leave blanks and do not report themselves as deadlocked over mitigating circumstances after reasonable deliberation, see Tr. of Oral Arg. 42, unless they are expressly instructed to do so.
The decision to exercise the power of the State to execute a defendant is unlike any other decision citizens and public officials are called upon to make. Evolving standards of societal decency have imposed a correspondingly high requirement of reliability on the determination that death is the appropriate penalty in a particular case. The possibility that petitioner’s jury conducted its task improperly certainly is great enough to require resentencing.
IV
We conclude that there is a substantial probability that reasonable jurors, upon receiving the judge’s instructions in this case, and in attempting to complete the verdict form as instructed, well may have thought they were precluded from considering any mitigating evidence unless all 12 jurors agreed on the existence of a particular such circumstance. Under our cases, the sentencer must be permitted to consider all mitigating evidence. The possibility that a single juror could block such consideration, and consequently require the jury to impose the death penalty, is one we dare not risk.
We therefore vacate the judgment of the Court of Appeals insofar as it sustained the imposition of the death penalty. The case is remanded to that court for further proceedings not inconsistent with this opinion.
It is so ordered.
APPENDIX TO OPINION OF THE COURT
FINDINGS AND SENTENCE DETERMINATION FORM EMPLOYED AT PETITIONER’S TRIAL
“Section I
“Based upon the evidence we unanimously find that each of the following aggravating circumstances which is marked ‘yes’ has been proven BEYOND A REASONABLE DOUBT and each aggravating circumstance which is marked ‘no’ has not been proven BEYOND A REASONABLE DOUBT:
“1. The victim was a law enforcement officer who was murdered while in the performance of his duties.
X
yes no
“2. The defendant committed the murder at a time when he was confined in a correctional institution.
X
yes no
“3. The defendant committed the murder in furtherance of an escape from or an attempt to escape from or evade the lawful custody, arrest or detention of or by an officer or guard of a correctional institution or by a law enforcement officer.
X
yes no
“4. The victim was a hostage taken or attempted to be taken in the course of a kidnapping or abduction or an attempt to kidnap or abduct.
X
yes no
“5. The victim was a child abducted in violation of Code, Article 27, § 2.
X
yes no
, “6. The defendant committed the murder pursuant to an agreement to contract for remuneration or the promise of remuneration to commit the murder.
X
yes no
“7. The defendant engaged or employed another person to commit the murder and the murder was committed pursuant to an agreement or contract for remuneration or the promise of remuneration.
X
yes no
“8. At the time of the murder, the defendant was under the sentence of death or imprisonment for life.
X
yes no
“9. The defendant committed more than one offense of murder in the first degree arising out of the same incident.
X
yes no
“10. The Defendant committed the murder while committing or attempting to commit robbery, arson or rape or sexual offense in the first degree.
X
yes no
“(If one or more of the above are marked ‘yes’, complete Section II. If all of the above are marked ‘no’, do not complete Sections II and III.)
“Section II
“Based upon the evidence we unanimously find that each of the following mitigating circumstances which is marked ‘yes’ has been proven to exist by A PREPONDERANCE OF THE EVIDENCE and each mitigating circumstance marked ‘no’ has not been proven by A PREPONDERANCE OF THE EVIDENCE:
“1. The defendant previously (i) has not been found guilty of a crime of violence; and (ii) has not entered a plea of guilty or nolo contendere to a charge of a crime of violence; and (iii) has not been granted probation on stay or entry of judgment pursuant to a charge or a crime of violence. As used in this paragraph, ‘crime of violence’ means abduction, arson, escape, kidnapping, manslaughter, except involuntary manslaughter, mayhem, murder, robbery, or rape or sexual offense in the first or second degree, or an attempt to commit any of these offenses, or the use of a handgun in the commission of a felony or another crime of violence.
X
yes no
“2. The victim was a participant in the defendant’s conduct or consented to the act which caused the victim’s death.
X
yes no
“3. The defendant acted under substantial duress, domination or provocation of another person, but not so substantial as to constitute a complete defense to the prosecution.
X
yes no
“4. The murder was committed while the capacity of the defendant to appreciate the criminality of his conduct or to conform his conduct to the requirements of law was substantially impaired, as a result of mental incapacity, mental disorder or emotional disturbance.
X
yes 3 o
5. The youthful age of the defendant at the time of the crime.
X
yes no
“6. The act of the defendant was not the sole proximate cause of the victim’s death.
X
yes no
“7. It is unlikely that the defendant will engage in further criminal activity that would constitute a continuing threat to society.
X
yes no
“8. Other mitigating circumstances exist, as set forth below:
None.
“(If one or more of the above in Section II have been marked ‘yes’, complete Section III. If all of the above in Section II are marked ‘no’, you do not complete Section III.)
“Section III
“Based on the evidence we unanimously find that it has been proven by A PREPONDERANCE OF THE EVIDENCE that the mitigating circumstances marked ‘yes’ in Section II outweigh the aggravating circumstances marked ‘yes’ in Section I.
yes no
“DETERMINATION OF SENTENCE
“Enter the determination of sentence either ‘Life Imprisonment’ or ‘Death’ according to the following instructions:
“1. If all of the answers in Section I are marked ‘no’ enter ‘Life Imprisonment.’
“2. If Section III was completed and was marked ‘yes’ enter ‘Life Imprisonment.’
“3. If Section II was completed and all of the answers were marked ‘no’ then enter ‘Death.’
“4. If Section III was completed and was marked ‘no’ enter ‘Death.’
“We unanimously determine the sentence to be Death. ” App. 99-103.
Among the mitigating circumstances, recognized by statute in Maryland, which the jury was instructed to consider, are:
“4. The murder was committed while the capacity of the defendant to appreciate the criminality of his conduct or to conform his conduct to the requirements of law was substantially impaired as a result of mental incapacity, mental disorder, or emotional disturbance.
“5. The youthful age of the defendant at the time of the crime.
“7. It is unlikely that the defendant will engage in further criminal activity that would constitute a continuing threat to society.
“8. Any other facts which the jury or the court specifically sets forth in writing that it finds as mitigating circumstances in the case.” Md. Ann. Code, Art. 27, § 413(g) (1987).
The defense introduced evidence, including the testimony of petitioner’s mother, demonstrating that petitioner had only a sixth-grade education, that he was 20 years old at the time of the murder, and that he had been in trouble from a young age. Since petitioner was 11 or 12 years old, his mother had been in contact with state agencies concerning his behavior. Petitioner underwent therapy as a child, was diagnosed as having “minimal brain damage,” and was placed on medication. Petitioner early developed drug and alcohol problems, and was assigned first to the German Children’s Home and then to the Maryland Training School for Boys. App. 45-53. At the time of the murder of his cellmate, petitioner was serving the second year of a 30-year sentence for an earlier murder in the second degree.
The jury was instructed to report their conclusions on a Findings and Sentence Determination form called for by Rule 772A. Prior to petitioner’s sentencing, Rule 772A was replaced by Maryland Rule of Procedure 4-343, which stipulated the use of a form similar to the one used in this case. The dissent below noted that the form provided under Rule 4-343 should have been used at petitioner’s trial, but concluded that no prejudice resulted to petitioner from the use of the similar, but incorrect, form. 310 Md. 33, 77, n. 2, 527 A. 2d 3, 24, n. 2 (1987). Petitioner has not raised here any objection about the use of the outdated form, as opposed to the then-prescribed form. The form actually used at petitioner’s trial, with the answers given, is set out in its entirety in the Appendix to this opinion.
The Court of Appeals of Maryland disposed of the claim on the merits despite petitioner’s failure, see App. 74; Tr. of Oral Arg. 12-13, to object to the verdict form or jury instructions at the sentencing proceeding. Presumably, the Court of Appeals found this appropriate either as review for plain error, see generally 3A C. Wright, Federal Practice and Procedure § 856 (2d ed. 1982), or because it concluded that Maryland law did not otherwise bar petitioner’s claim. In any event, in view of the Maryland court’s review on the merits, our jurisdiction over the federal constitutional question is established. See, e. g., Orr v. Orr, 440 U. S. 268, 274-275 (1979); Franks v. Delaware, 438 U. S. 154, 161-162 (1978).
We note, in passing, that counsel for petitioner had filed a pretrial motion in which he asserted generally: “That Article 27, Section 413 and 414, and Maryland Rule 772 unconstitutionally restrict the discretion of the finder of fact in determining whether the death penalty should be imposed.” Record 24.
At the time of petitioner’s trial, § 413(k)(2) provided:
“If the jury, within a reasonable time, is not able to agree as to sentence, the court shall dismiss the jury and impose a sentence of imprisonment for life.” See 310 Md., at 55, 527 A. 2d, at 13.
By 1987 Md. Laws, ch. 237, effective July 1,1987, § 413(k)(2) was amended to read:
“If the jury, within a reasonable time, is not able to agree as to whether a sentence of death shall be imposed, the court may not impose a sentence of death.”
We perceive nothing significant for petitioner’s case in this 1987 amendment.
Section 413(b) affords the convicted capital defendant a choice between sentencing by the judge or by the jury. In this case, petitioner invoked his right to be sentenced by his jury. Our discussion of Maryland’s sentencing scheme is limited to that context.
Indeed, the Court of Appeals contemplated only two alternative lawful consequences of a lack of unanimity to accept or reject a mitigating circumstance: the jury could deadlock, requiring the imposition of a life sentence, or, as that court has now prescribed, the jury could proceed to the balancing stage where each juror would consider all the evidence in mitigation to reach a conclusion as to whether the death penalty was warranted.
No one has argued here, nor did the Maryland Court of Appeals suggest, that mitigating evidence can be rendered legally “irrelevant” by one holdout vote.
Under Maryland law, the jury was not free at this stage to decide that the relevant facts, even if proved, did not have a mitigating effect. That decision already has been made by the state legislature. See § 413(g); see also Tr. of Oral Arg. 38-40. The jury’s discretion in attaching significance to the presence of mitigating circumstances is properly exercised at the subsequent balancing stage in the process. See § 413(h).
In Andres v. United States, the Court construed a federal statute that required imposition of the death penalty for first-degree murder unless the guilty verdict was “qualified” by the addition of the phrase “without capital punishment.” See 333 U. S., at 742, and n. 1. The Court concluded that the statute required the jury to be unanimous both as to guilt and as to whether the death penalty should be imposed rather than, as the Government contended, requiring that the death penalty be imposed unless the jury unanimously agreed to impose the qualification. The Court of Appeals for the Ninth Circuit had also rejected the Government’s contention and arrived at a construction of the statute similar to that of this Court, but found that the jury instructions had conveyed the proper construction to the jury. This Court disagreed, finding that under the instructions the jury received, they might “reasonably conclude that, if they cannot all agree to grant mercy, the verdict of guilt must stand unqualified.” Id., at 752.
We find puzzling the dissent’s citation, post, at 394, of Jurek v. Texas, 428 U. S. 262, 279 (1976) (White, J., concurring in judgment), a case in which the Court upheld the very different sentencing procedure followed in Texas. While juries indeed may be capable of understanding the issues posed in capital sentencing proceedings, they must first be properly instructed.
As the dissent ably reports, the trial judge stressed “[o]ver and over again,” post, at 393, that the jury’s findings had to be unanimous. But not once in any of those instructions did the trial court explain to the jury that if it could not reach unanimity to answer “yes,” it could do something other than answer “no.” The dissent, like the trial court, confuses repetition with clarity, pronouncing “over and over again” that there was only one way the jury could have understood its instructions. See post, at 391, 392, 393, and 394. Not even the Maryland Court of Appeals believed that. See, infra, at 381-383.
At the conclusion of Section II, once again, the instructions were to the effect that the failure to answer “yes” to any question obtained the same consequence as answering “no” to all questions: “[I]f one or more of the above in section two have been marked yes, then you go on to section three. If all of the above in section two are marked no, then you do not complete section three.” App. 73.
The jury in this case apparently never reached the balancing stage of the process. When the jury returned to the courtroom to report its verdict, even the judge was confused by their failure to complete Section III, in accordance with the form’s instructions. See App. 96. The prosecutor suggested, during a colloquy with the court, that the jurors were “hung up on that language.” Ibid.
For example, some jurors in this case might have found that petitioner’s age, 20, constituted a mitigating factor, i. e., youthfulness, under § 413(g)(5). Indeed, in his sentencing report the trial judge noted: “There was evidence from which the jury could have found the existence of Mitigating Circumstance No. 5 (youthful age).” App. 108. Other jurors, on the other hand, might have accepted the prosecutor’s argument that petitioner was “not youthful in terms of the criminal justice system,” id., at 79, because of his history of criminal activity. Under such circumstances, the lack of unanimity would have prevented the jury from marking that answer “yes.” Regardless of whether the answer was marked “no” or left blank, the instructions in Section III would prevent those jurors who thought petitioner’s youthfulness was relevant to the ultimate sentencing decision from giving that mitigating circumstance any weight.
Petitioner has lodged with this Court copies of the sentencing forms used in those two cases. In Wooten-Bey v. State the new sentencing form appears to have made a significant difference: The jury found one aggravating circumstance, but failed to agree on any mitigating circumstance. It did, however, report three statutory mitigating circumstances as found by one or more but fewer than all 12 jurors. The jury also articulated three nonstatutory mitigating circumstances, as found by one or more, but not all, jurors. The jury then reported that it did not unanimously find that the aggravating circumstances marked “proven” outweighed the mitigating circumstances, and unanimously fixed the sentence at life imprisonment. See Findings and Sentencing Determination in No. C. T. 83-1497C (Cty. Ct., Prince George’s Cty., 1987). ‘
In Doering v. State the jury used a verdict form apparently containing aspects of both the old and new forms. The jurors were instructed that in the event one or more of them found a mitigating circumstance not agreed to by all 12, they could leave that answer blank. The jury exercised that option with respect to one statutory mitigating circumstance. The jury also articulated an additional nonstatutory mitigating circumstance found by one or more but not all 12 jurors. Upon balancing aggravating against mitigating circumstances, the jury sentenced the defendant to death. See Findings and Sentencing Determination in No. 86-CR-6128 (Cty. Ct., Baltimore Cty., 1987).
Because our conclusion on this issue is sufficient to dispose of the case, we refrain from any review of the Court of Appeals’ sua sponte declaration, see 310 Md., at 72, n. 14, 527 A. 2d, at 22, n. 14, that no “victim impact statement” was introduced in evidence in contravention of our decision last Term in Booth v. Maryland, 482 U. S. 496 (1987).