**3Petitioner pled guilty to four counts of murder and 25 counts of attempted murder, as well as pleading no contest to a twenty-sixth count of attempted murder. As part of a plea bargain, petitioner and the state agreed that he would receive concurrent 25-year sentences for the four murders. They also agreed that each side would be free to argue that the mandatory 90-month sentences for each of the attempted murders should run consecutively or concurrently. After a six-day sentencing hearing, the trial court ordered that 50 months of each 90-month sentence for attempted murder would run concurrently but that 40 months of each of those sentences would run consecutively to each other and to the four concurrent 25-year sentences. As a result of that ruling, petitioner's aggregate sentence totals slightly less than 112 years.

In this post-conviction proceeding, petitioner argues that, because he was a juvenile when he committed his crimes, the Eighth Amendment prohibits the imposition of an aggregate sentence that is the functional equivalent of a life sentence without the possibility of parole. Petitioner's federal argument entails primarily three issues. The first is whether, as a matter of state law, petitioner's Eighth Amendment claim is procedurally barred. See ORS 138.550(2) (barring post-conviction petitioners from raising grounds for relief that were or reasonably could have been raised on direct appeal); Verduzco v. State of Oregon , 357 Or. 553, 355 P.3d 902 (2015) (applying a related statute). If it is, the second issue is whether Montgomery v. Louisiana , --- U.S. ----, 136 S.Ct. 718, 193 L.Ed. 2d 599 (2016), requires this court to reach petitioner's Eighth Amendment claim despite the existence of that state procedural bar. Third, if petitioner's Eighth Amendment claim is not procedurally barred, the remaining issue is whether and how Miller v. Alabama , 567 U.S. 460, 132 S.Ct. 2455, 183 L.Ed. 2d 407 (2012), applies when a court imposes an aggregate sentence for multiple crimes committed by a juvenile.

As explained below, we hold that, even if ORS 138.550(2) does not pose a procedural bar to petitioner's Eighth Amendment claim, his claim fails on the merits.

**4More specifically, the issue in Miller was whether the Eighth Amendment prohibited a juvenile from being sentenced to life imprisonment without the possibility of parole for a single homicide. The Court held that such a sentence could be imposed but only if the trial court found that the crime reflected irreparable corruption rather than the transience of youth. The Court did not consider in Miller whether a juvenile who has been convicted of multiple murders and attempted murders, as in this case, may be sentenced to an aggregate *403consecutive sentence that is the equivalent of life without the possibility of parole. This case thus poses a different issue from the issue in Miller . Beyond that, we conclude that the facts in this case, coupled with the sentencing court's findings, bring petitioner within the narrow class of juveniles who, as Miller recognized, may be sentenced to life without the possibility of parole.

I. FACTS

On May 20, 1998, when petitioner was 15 years old, he was sent home from high school for bringing a gun to school. Later that day, he shot his father once in the head. Afterwards, he shot his mother five times in the head and once in the heart. He left their bodies in the house but covered each with a sheet. The next morning, petitioner got the morning paper, had a bowl of cereal, and later drove his mother's car to the high school. Petitioner wore a trench coat, under which he concealed three guns: a Ruger .22 pistol with a ten-round clip; a Ruger 10/22 rifle with a banana clip that held 50 rounds; and a Glock 9 mm pistol. The stock of the rifle had been modified to create a pistol grip, which allowed the rifle to be concealed more easily.

As petitioner entered a breezeway at school, he called to one of his friends and told him not to go into the cafeteria that day. He then began walking forward, took the rifle out of his trench coat, pointed it at a classmate's head, and pulled the trigger. When the rifle misfired, he "was like mad and upset." After adjusting the rifle, he "[s]hot [the student] in the back of the head." Petitioner then "turned and started walking south * * * towards the cafeteria" until he came upon another student whom he shot in the face.

**5After that, he "just walked forward to the cafeteria door and opened up the door and started shooting."

One of the students in the cafeteria thought "it was a joke or something" until he realized that "there was blood coming from [another student]." One student stood up when petitioner began shooting, and petitioner shot her in the head. As another student testified, "it look[ed] lik[e] he aimed at her head." Petitioner began "walking towards the center of the cafeteria and shooting towards the line where people [we]re getting food and snacks." One student dove under a table, and petitioner "walked up and shot that person" in the head. Petitioner then started shooting towards the door "where there's some more kids standing by a table." He put the rifle to a classmate's head and pulled the trigger, but there were no more bullets in the clip. At that point, two students "jump[ed] up and tackle[d]" petitioner. Although petitioner shot one of those students, they were able to subdue petitioner and take his guns.

That day, petitioner killed two students. Two of the students whom he shot in the head survived but were permanently affected. Of the remaining students whom petitioner shot, some nearly died, others were injured in ways that substantially impaired them, while still others recovered physically from their bullet wounds. As a result of petitioner's actions, the state charged him with, among other things, four counts of aggravated murder and 26 counts of attempted aggravated murder. The four counts of aggravated murder were based on killing his parents one day and two students the next day. Twenty four of the 26 counts of attempted aggravated murder were based on the 24 students whom petitioner allegedly shot and wounded but did not kill.1 One count of attempted aggravated murder was **6based on the student whom he attempted to kill but did not because the clip ran out of bullets. The final count of attempted aggravated murder arose when, after his arrest, petitioner attempted to kill a police officer with a knife that he had concealed on his person. *404Before trial, petitioner moved to dismiss the aggravated murder charges, arguing that "[t]he possibility of a sentence of life in prison without the possibility of parole for a fifteen year old convicted of murder constitutes cruel and unusual punishment in violation of * * * the Eighth Amendment to the U.S. Constitution." The arguments that petitioner advanced in the memorandum in support of his motion paralleled the arguments that the United States Supreme Court later found persuasive in Miller ; that is, he argued that the prohibition on sentencing a 15-year old to death should be extended to life without the possibility of parole because of the immaturity of juveniles and their possibility for change. Based on that argument, petitioner asked the sentencing court to declare Oregon's aggravated murder statutes "unconstitutional insofar as these statutes extend the possibility of a true life sentence [a life sentence without the possibility of parole] to a fifteen year old convicted of aggravated murder." The sentencing court denied petitioner's motion to dismiss, and petitioner entered into the plea agreement.

As part of that agreement, petitioner pled guilty to the lesser included offenses of murder and attempted murder. Under Oregon law, his plea meant that petitioner admitted intentionally killing the four people whom he shot and intending to kill the nearly two dozen students whom he shot and wounded and the one student whom he attempted to shoot.2 Additionally, petitioner stated as part of his plea that, "[b]y permitting the Court to enter a guilty plea on my behalf, I knowingly waive the defenses of mental disease or defect, extreme emotional disturbance, or diminished capacity."3

**7The plea petition recites that petitioner was aware that, as a result of his plea, the trial court was "bound and shall impose a 300 month sentence (25 years) on each [of the four convictions of murder] with those sentences to be served concurrently." Regarding the remaining 26 counts of attempted murder, petitioner acknowledged that he would receive a mandatory sentence of 90 months on each count, that the trial court was not bound to order that the sentences be served concurrently, and that each side was free to argue for consecutive or concurrent sentences.

The sentencing court held a six-day hearing to determine whether the sentences on the 26 attempted murder charges should be concurrent or consecutive. At the hearing, the court considered a presentence investigation report that detailed petitioner's background. It heard an abbreviated recitation of the events that occurred at the high school and also what the officers found when they went to petitioner's home after the shooting. In addition to describing the discovery of his parents' bodies and evidence regarding the manner of their death, the officers described the writings they found in petitioner's room, books they found in his room discussing making explosive devices, and multiple explosive devices secreted throughout petitioner's home.

In mitigation, petitioner submitted evidence from his sister, former teachers, and neighbors who commented on positive aspects of his character. The majority of petitioner's mitigation evidence, however, consisted of expert testimony regarding his mental health. His experts presented evidence that petitioner had been hearing voices for the past three years and that one of the voices had commanded him to commit the murders and attempted murders. Although acknowledging some difficulties in diagnosing adolescents, petitioner's medical experts concluded that he suffered from paranoid schizophrenia or a schizoaffective disorder that combines some of the essential features of schizophrenia and depression.

One of petitioner's experts, Dr. Sack, is a child and adolescent psychiatrist who previously chaired the department of child psychiatry at Oregon Health Sciences University. Sack concluded that, although he could not *405**8"pigeonhole [petitioner] into one psychotic box or the other," petitioner's "crimes and his behavior on [May 20 and 21] were directly the product of a psychotic process that had been building intermittently in him over a three-year period."4 He explained that petitioner's psychosis was treatable, but he cautioned that he could not "claim that it's curable." That is, the psychosis could be managed if petitioner recognized it and accepted treatment, but if petitioner did not treat the psychosis, "he would be a dangerous person." As Sack explained, the "crime [that petitioner committed] is so bizarre, and it so fits with what we know about paranoid schizophrenics, who are dangerous people."

Another of petitioner's experts, Dr. Bolstad, is a psychologist who works extensively with juvenile offenders. He agreed with Sack that petitioner's condition could be treated and that, with continued treatment and supervision, petitioner could be a candidate for release. However, Bolstad also agreed with Sack that petitioner's condition could not be cured. As he testified on cross-examination, "I personally don't think there is any way of curing [petitioner's] disorder. There's not a cure for it, okay? I do think it can be managed," principally with psychotropic medicine. Bolstad then added:

"Real frankly, I would not want to see [petitioner] out on the streets, ever, with this condition, okay? Without medicine and without an awful lot of structure and support services arranged for him."5

Petitioner also argued that the trial court should consider his youth when imposing his sentence. More specifically, he incorporated the arguments that he previously had made against imposing a life sentence without possibility of parole for aggravated murder and contended that those same considerations applied equally to imposing consecutive sentences that were equivalent to a life sentence without the possibility of parole. In making that argument, petitioner's **9counsel advanced virtually the same arguments that later informed the Court's decision in Miller ; that is, he argued that Thompson v. Oklahoma , 487 U.S. 815, 108 S.Ct. 2687, 101 L.Ed. 2d 702 (1988), which had categorically prohibited imposing the death penalty on juveniles under 16 years of age, should be extended to aggregate sentences imposed on a juvenile that were equivalent to a life sentence without the possibility of parole.6

In addition to those considerations, the court also heard from the surviving students who had been shot, as well as from the students' parents. Each of the students who spoke told the court how petitioner's actions had affected their lives-the loss of their classmates, the loss of the use of their limbs, the loss of part of their childhood, and their difficulty trying to come to terms with that loss. Some parents spoke of losing their children. Others spoke of coming to the school on learning of the shooting, waiting to hear whether their children had been shot, and, if their children had been shot but survived, the difficulty of coping with their children's injuries and trying to move past the harm that petitioner had inflicted on their families.

In determining the appropriate sentence, the trial court began by comparing petitioner's case to the cases of two young homicide offenders7 who previously had been before the court. One had received a 25-year sentence; the other, a sentence of life with the possibility of parole after 30 years, conditioned on the availability of treatment and other safeguards to ensure that the offender *406was no longer a danger to society. The court explained that the facts in those cases "pale[d] in the light of the facts" in petitioner's case and concluded that a similar sentence would not be "proportional to those sentences or to these present facts."

The court recognized that petitioners' experts had "necessarily and appropriately focused on [petitioner] and on his condition," and that they "generally agree[d] that with extensive, long-term treatment, they would not expect **10him to be dangerous to others." The court observed, however, that petitioner's experts had agreed that, "[u]ntreated, or I suppose improperly or incompletely treated, [petitioner] is and remains dangerous." The sentencing court noted that "[o]ne of the last things Dr. Bolstad said was to the effect that there is no cure for [petitioner's] condition, that he should never be released without appropriate medication and-I quote-'an awful lot of structure and appropriate support services arranged for him.' "

After expressing concern that the system might not be able to provide the necessary level of treatment and support, the court observed that, given the mandatory nature of the sentences for attempted murder, it lacked the flexibility to "structure any kind of long-range conditional sentence." The court added, however, that, even if it had that authority, it would not be appropriate to exercise it. The court explained that, after listening to the effect that petitioner's actions had had on his classmates and their families, "[i]t became very apparent yesterday that this sentence needed to account for each of the wounded, who rightly call themselves survivors, and for [petitioner] to know that there was a price to be paid for each person hit by his bullets."

The trial court accordingly divided each mandatory 90-month sentence for attempted murder into two parts. It provided that 40 months of each 90-month sentence would run consecutively to each other and to the four 25-year concurrent sentences for murder, while 50 months of each of those 26 sentences would run concurrently. The sentencing court structured the aggregate sentence to ensure that petitioner would serve 40 months (three-and-one-third years) for each of the students whom he shot with the intent to kill, for the student whom he attempted to shoot in the head but ran out of bullets, and for the officer whom he charged with a knife. As noted, imposing a consecutive 40-month sentence on each of petitioner's 26 attempted murder convictions, when run consecutively to his four concurrent 25-year sentences for murder, results in an aggregate sentence of slightly less than 112 years.

Petitioner challenged his aggregate sentence on direct appeal, contending primarily that it violated **11Article I, section 16, of the Oregon Constitution. He added in a footnote that his "true-life sentence violates the Eighth Amendment's ban on cruel and unusual punishment, for it is 'grossly disproportionate' to the crime." (Quoting Harmelin v. Michigan , 501 U.S. 957, 1001, 111 S.Ct. 2680, 115 L.Ed. 2d 836 (1991).) The Court of Appeals rejected petitioner's state constitutional argument, as well as his Eighth Amendment claim. State v. Kinkel , 184 Or. App. 277, 56 P.3d 463, rev. den. , 335 Or. 142, 61 P.3d 938 (2002). A year later, petitioner filed a timely post-conviction petition, challenging his conviction. The post-conviction court denied that petition, the Court of Appeals affirmed, and this court denied review. Kinkel v. Lawhead , 240 Or. App. 403, 246 P.3d 746, rev. den. 350 Or. 408, 256 P.3d 121 (2011).

The United States Supreme Court did not issue its decision in Miller until 2012, approximately a year after petitioner's first post-conviction petition had become final. After the Court decided Miller , petitioner filed a second post-conviction petition, once again raising an Eighth Amendment challenge to his sentence but this time relying on the reasoning in Miller . The post-conviction court ruled that the state post-conviction statutes barred petitioner from raising his Eighth Amendment claim in his second post-conviction petition because he reasonably could have raised that ground for relief in his first post-conviction petition. See ORS 138.550(3) (prohibiting successive petitions if the ground for relief reasonably could have been raised in the preceding petition).

The Court of Appeals affirmed the post-conviction court's judgment, but it did so based on a related procedural statute, *407ORS 138.550(2). That subsection provides that "no ground for relief may be asserted by [a] petitioner in a petition for review under [Oregon's post-conviction statutes] unless such ground was not asserted and could not reasonably be asserted in the direct appellate review proceeding." ORS 138.550(2) ; see Kinkel v. Persson , 276 Or. App. 427, 443, 367 P.3d 956 (2016) (applying that statutory bar). Although petitioner argued that he could not reasonably have raised his Eighth Amendment claim until after the United States Supreme Court decided Miller , the Court **12of Appeals explained that petitioner had in fact raised that ground for relief on direct appeal. Id. at 442-44, 367 P.3d 956.

Following this court's decision in Verduzco , the Court of Appeals reasoned that the fact that Miller had not yet been decided when petitioner filed his direct appeal did not mean that the procedural bar in ORS 138.550(2) was inapplicable. Id. It also rejected petitioner's argument that federal law, as a result of the Court's decision in Montgomery , overrode the procedural bar set out in ORS 138.550(2). Kinkel , 276 Or. App. at 438 n. 6, 367 P.3d 956. The Court of Appeals accordingly affirmed the post-conviction court's judgment. We allowed this petition for review to consider whether petitioner's Eighth Amendment claim is procedurally barred in state court and, if not, whether his aggregate sentence violates the Eighth Amendment.

II. ORS 138.550(2)

The state argues that ORS 138.550(2) provides a complete answer to petitioner's Eighth Amendment claim. It contends, and the Court of Appeals agreed, that ORS 138.550(2) precludes petitioner from relitigating in a state post-conviction proceeding the same ground for relief that he litigated on direct appeal.8 Petitioner responds that the United States Supreme Court decisions interpreting the Eighth Amendment underwent a fundamental shift after he filed his opening brief on direct appeal in 2001. He contends that the Eighth Amendment claim that he is raising now differs from the claim he raised at his sentencing hearing and that his current claim could not reasonably have been raised or adjudicated in 2001. It follows, he concludes, that ORS 138.550(2) does not bar the state courts from reaching the federal claim that he raised in his second post-conviction petition.

We need not resolve the parties' procedural arguments to decide this case. Even if we assume that petitioner **13is not procedurally barred from relitigating his Eighth Amendment claim on state post-conviction, we conclude that the Court of Appeals decision may be affirmed on an alternative ground. Petitioner's Eighth Amendment challenge to his sentence fails on the merits. Before explaining why we reach that conclusion, we first describe two lines of Eighth Amendment authority. One involves categorical Eighth Amendment limits on juvenile sentencing; the other, the limits that the Eighth Amendment places on a court's ability to impose consecutive sentences for multiple crimes. We then explain why we conclude that, in light of the sentencing court's findings, petitioner's aggregate sentence complies with the Eighth Amendment.

III. EIGHTH AMENDMENT

Eighth Amendment proportionality cases "fall within two general classifications." Graham v. Florida , 560 U.S. 48, 59, 130 S.Ct. 2011, 176 L.Ed. 2d 825 (2010). One involves challenges to a term of years in light of all the circumstances of a particular case. Id. at 59-60, 130 S.Ct. 2011 (citing Solem v. Helm , 463 U.S. 277, 103 S.Ct. 3001, 77 L.Ed. 2d 637 (1983) ). The other involves categorical limits on certain sentencing practices. Id. at 61, 130 S.Ct. 2011. In this case, petitioner argues that the categorical rule announced in Miller applies to his aggregate sentence. In analyzing petitioner's argument, we accordingly focus on the Court's cases that have announced categorical rules for sentencing juvenile offenders.

*408A. Categorical sentencing limitations

Generally, in determining whether a categorical rule applies, the Court has looked to "objective indicia of society's standards, as expressed in legislative enactments and state practice," and it also has relied on its own "exercise of independent judgment [regarding proportionality, which entails] consideration of the culpability of the offenders at issue in light of their crimes and characteristics, along with the severity of the punishment in question." See Graham , 560 U.S. at 61, 67, 130 S.Ct. 2011 (internal quotation marks and citation omitted). The Court looked to both considerations in concluding that juveniles are not eligible for the death penalty, **14Roper v. Simmons, 543 U.S. 551, 125 S.Ct. 1183, 161 L.Ed.2d 1 (2005), and that juveniles convicted of a nonhomicide offense may not be sentenced to life imprisonment without the possibility of parole, Graham , 560 U.S. at 75, 130 S.Ct. 2011. In contrast to Roper and Graham , the Miller Court relied on a proportionality analysis in holding that not every juvenile who commits a murder is eligible for life imprisonment without the possibility of parole. Miller , 567 U.S. at 479, 132 S.Ct. 2455.9 Only those juveniles whose homicide reflects irreparable corruption rather than the transience of youth are eligible for a life sentence without possibility of parole. See Montgomery , 136 S.Ct. at 734 (interpreting Miller ).

Following Miller , petitioner relies solely on a proportionality analysis in arguing that the rule from that case applies to his sentence. Because petitioner does not identify any objective indicia of society's standards to support his categorical Eighth Amendment claim, we limit our discussion to the proportionality analyses in Roper , Graham , and Miller . Although those analyses are similar in many respects, they also differ in ways that bear on petitioner's Eighth Amendment argument. Accordingly, we first describe briefly the proportionality analysis in each of those cases before describing a separate line of Eighth Amendment cases regarding aggregate sentences.

In Roper , the Court concluded that the unique characteristics of juveniles made that class of offenders ineligible for the death penalty. The Court observed that

" '[a] lack of maturity and an underdeveloped sense of responsibility are found in youth more often than in adults and are more understandable among the young. These qualities often result in impetuous and ill-considered actions and decisions.' "

Roper , 543 U.S. at 569, 125 S.Ct. 1183 (quoting Johnson v. Texas , 509 U.S. 350, 367, 113 S.Ct. 2658, 125 L.Ed. 2d 290 (1993) ). It noted that juveniles, as a class, are more "vulnerable or susceptible to **15negative influences and outside pressures, including peer pressure." Id. Finally, the Court noted that a juvenile's character and personality traits are "more transitory, less fixed." Id. at 570, 125 S.Ct. 1183. It followed from those considerations that juveniles are not, as a class, as culpable as adults and possess greater capacity for reform, with the result that the penological justifications for the death penalty-retribution and deterrence-apply with less force to juveniles. Id. at 571, 125 S.Ct. 1183. In light of those considerations and the severity of the sentence, the Court concluded that imposing the death penalty on a juvenile was too harsh and too final to comply with the Eighth Amendment.

Graham considered how the constitutional balance is struck when a juvenile is sentenced to life without possibility of parole for a nonhomicide offense. The Court began from the proposition that, although death is different in kind from other punishments, life without the possibility of parole is comparable in terms of severity when applied to a juvenile. Graham , 560 U.S. at 69-70, 130 S.Ct. 2011. Moreover, the Court explained that "defendants who do not kill, intend to kill, or foresee that life will be taken are *409categorically less deserving of the most serious forms of punishment than are murderers." Id. at 69, 130 S.Ct. 2011. It followed that not only are juveniles generally less culpable than adults who commit the same crime but the nature of the crime (a nonhomicide offense) called for less serious punishment. The Court reasoned that, "when compared to an adult murderer, a juvenile offender who did not kill or intend to kill has a twice diminished moral culpability. Age and the nature of the crime each bear on the analysis." Id. Given a juvenile's lesser culpability and greater potential for reform, the Court held that the Eighth Amendment categorically bars a sentence of life without possibility of parole for a nonhomicide offense committed by a juvenile.

In Miller , the Court relied on the proportionality reasoning in Roper and Graham to hold that imposing a mandatory life sentence on a juvenile who commits a homicide violates the Eighth Amendment. See 567 U.S. at 470-74, 132 S.Ct. 2455. Specifically, the Court held that a factfinder must be able to make an individualized determination whether a life sentence without possibility of parole is appropriate when **16a juvenile is convicted of homicide. Id. at 479, 132 S.Ct. 2455. The Court observed that "appropriate occasions for sentencing juveniles to this harshest possible penalty will be uncommon," particularly "because of the great difficulty [the Court] noted in Roper and Graham of distinguishing at this early age between 'the juvenile offender whose crime reflects unfortunate yet transient immaturity, and the rare juvenile offender whose crime reflects irreparable corruption.' " Id. at 479-80, 132 S.Ct. 2455 (quoting Roper , 543 U.S. at 573, 125 S.Ct. 1183 ). The Court explained, however, that the Eighth Amendment did not foreclose a court from sentencing a juvenile who has committed a homicide to life without the possibility of parole. Id. at 480, 132 S.Ct. 2455.

Later, in Montgomery , the Court concluded that Miller announced a substantive limitation as well as a procedural requirement of an individualized sentencing hearing when a juvenile is convicted of homicide. As the Court explained in Montgomery ,

"Even if a court considers a child's age before sentencing him or her to a lifetime in prison, that sentence still violates the Eighth Amendment for a child whose crime reflects ' "unfortunate yet transient immaturity." ' [ Miller , 567 U.S.] at 479 [132 S.Ct. 2455] (quoting Roper , 543 U.S. at 573 [125 S.Ct. 1183] ). Because Miller determined that sentencing a child to life without parole is excessive for all but ' "the rare juvenile offender whose crime reflects irreparable corruption," ' id. at 479-80 [132 S.Ct. 2455] (quoting Roper , 543 U.S., at 573 [125 S.Ct. 1183] ), it rendered life without parole an unconstitutional penalty for 'a class of defendants because of their status'-that is, juvenile offenders whose crimes reflect the transient immaturity of youth. Penry , 492 U.S., at 330, 109 S.Ct. 2934."

136 S.Ct. at 734.10

In both Miller and Graham , the severity of the punishment (life without possibility of parole) and the nature of the offender (a juvenile) were the same. Only one factor differed: the nature of the offense. The different categorical rules that the Court announced in those cases resulted from **17the differing offenses at issue in each case, a nonhomicide in one and a homicide in the other. The Court expressly recognized that point when it explained in Miller that " Graham established one rule (a flat ban [on life without possibility of parole] ) for nonhomicide offenses, while we set out a different one (individualized sentencing) for homicide offenses." See Miller , 567 U.S. at 474 n. 6, 132 S.Ct. 2455. Similarly, the Court reaffirmed in Miller that a juvenile's "moral culpability [for homicide] and [the] consequential harm" of that offense justified a more severe sanction than a nonhomicide offense. See id. (distinguishing Graham ).

At this juncture in our analysis, one other aspect of the Court's juvenile sentencing cases warrants mention. To date, the Court *410has not extended its holdings in Roper , Miller , and Graham to lesser minimum sentences. See Graham , 560 U.S. at 124, 130 S.Ct. 2011 (Alito, J., dissenting) ("Nothing in the Court's opinion affects the imposition of a sentence to a term of years without the possibility of parole."); id. at 123, 130 S.Ct. 2011 n. 13 (Thomas, J., dissenting) (making that observation);11 cf. Miller , 567 U.S. at 475, 132 S.Ct. 2455 (recognizing that Graham 's prohibition on sentencing juveniles to life without possibility of parole for a nonhomicide offense was "unprecedented for a [lesser] term of imprisonment").

Consistently, petitioner does not argue that sentencing him to a 25-year prison term without the possibility of parole for a single murder or 40 months without the possibility of parole for a single attempted murder violates the Eighth Amendment. Rather, his argument rests on the proposition that, even though each sentence for each of his crimes may be constitutionally permissible, running his attempted murder sentences consecutively to each other and to his concurrent murder sentences results in an aggregate sentence that is equivalent to life without the possibility of parole and, as a result, violates the Eighth Amendment. Before turning to petitioner's argument that the reasoning **18in Miller and Graham applies with equal force to aggregate sentences, we first describe briefly a line of federal authority that touches on aggregate sentencing.

B. Eighth Amendment limits on aggregate sentences

In considering the constitutionality of an aggregate sentence, the United States Supreme Court observed over 125 years ago:

" 'If [a defendant sentenced to an aggregate sentence for multiple offenses] has subjected himself to a severe penalty, it is simply because he has committed a great many such offenses. It would scarcely be competent for a person to assail the constitutionality of the statute prescribing a punishment for burglary on the ground that he had committed so many burglaries that, if punishment for each were inflicted on him, he might be kept in prison for life. The mere fact that cumulative punishments may be imposed for distinct offenses in the same prosecution is not material upon this question. If the penalty were unreasonably severe for a single offense, the constitutional question might be urged; but here the unreasonableness is only in the number of offenses which the [defendant] has committed.' "

O'Neil v. Vermont , 144 U.S. 323, 331, 12 S.Ct. 693, 36 L.Ed. 450 (1892) (quoting State v. O'Neil , 58 Vt. 140, 2 A. 586, 593 (1886) ). To be sure, the passage quoted above was dicta for purposes of the issues facing the United States Supreme Court in O'Neil .12 However, later courts have found the Court's reasoning persuasive. See, e.g. , Pearson v. Ramos , 237 F.3d 881, 886 (7th Cir. 2001) ("Every disciplinary sanction, like every sentence, must be treated separately, not cumulatively, for purposes of determining whether it is cruel and unusual."); Hawkins v. Hargett , 200 F.3d 1279, 1285 n. 5 (10th Cir. 1999) ("The Eighth Amendment analysis focuses on the sentence imposed for each specific crime, not on the cumulative sentence for multiple crimes."); United States v. Aiello , 864 F.2d 257, 265 (2d Cir. 1988) ("Eighth amendment **19analysis focuses on the sentence imposed for each specific crime, not on the cumulative sentence.").13 *411C. Petitioner's arguments

Given those two lines of Eighth Amendment cases, we think that the initial question this case presents is how Miller and Graham apply when a juvenile receives an aggregate life sentence for multiple murders and attempted murders. As we understand petitioner's argument, he contends that the number and nature of his offenses should not be a factor in striking an Eighth Amendment proportionality balance. Rather, he appears to argue that, when a juvenile's aggregate sentence is equivalent to life without possibility of parole, then the severity of the sentence coupled with the characteristics of juvenile offenders will always lead to the conclusion that a life sentence without possibility of parole will violate the Eighth Amendment.

The holdings in Miller and Graham do not compel the categorical rule that petitioner urges. The question in Miller was whether a juvenile who had committed a single homicide could be sentenced to life imprisonment without the possibility of parole for that crime.14 Graham is **20similarly limited. In that case, the question was whether a juvenile convicted of a single nonhomicide offense could be sentenced to life without parole. See Graham , 560 U.S. at 48, 63, 130 S.Ct. 2011 ("The instant case concerns only those juvenile offenders sentenced to life without parole solely for a nonhomicide offense.").15 The Court neither considered nor decided in Miller and Graham how the categorical limitations that it announced for a single sentence for one conviction would apply to an aggregate sentence for multiple convictions.

It follows that the holdings in Miller and Graham do not dictate the result when a juvenile is convicted of multiple murders and attempted murders, as petitioner was. Moreover, the reasoning in those cases leads us to conclude that the inquiry for a sentencing court in imposing an aggregate sentence is not as narrow as petitioner perceives. Contrary to petitioner's argument, Miller and Graham do not limit a sentencing court to considering only the severity of the sentence and the nature of the offender. Rather, those decisions make clear that a sentencing court can and should consider the nature and number of the juvenile offender's convictions.

For example, Graham explained that determining whether a sentencing practice is categorically disproportionate "requires consideration of the culpability of the offenders at issue in light of their crimes and [their personal] characteristics, along with the severity *412of the punishment in question." 560 U.S. at 67, 130 S.Ct. 2011 (emphasis added). As the Court also stated in Graham , "the age of the offender and the nature of the crime [in that case, a nonhomicide **21offense] each bear on the analysis." Id. at 69, 130 S.Ct. 2011. As noted above, the one fact that categorically precluded imposition of life without parole on any juvenile offender in Graham but permitted the imposition of that punishment on some juvenile offenders in Miller was the nature of the offense. As the Court explained in Miller , " Graham established one rule (a flat ban) for nonhomicide offenses, while we set out a different one (individualized sentencing) for homicide offenses." 567 U.S. at 474 n. 6, 132 S.Ct. 2455. That was true, even though, as Miller noted, none of what the Court had said about juveniles in Graham and Roper -their "distinctive (and transitory) mental traits and environmental vulnerabilities-is crime-specific." Id. at 473, 132 S.Ct. 2455.

Put simply, "[j]uvenile offenders who commi[t] both homicide and nonhomicide crimes present a different situation for a sentencing judge than juvenile offenders who committed no homicide." Graham , 560 U.S. at 63, 130 S.Ct. 2011.16 It follows that the reasoning in Graham and Miller permits consideration of the nature and the number of a juvenile's crimes in addition to the length of the sentence that the juvenile received and the general characteristics of juveniles in determining whether a juvenile's aggregate sentence is constitutionally disproportionate.

Given the nature and the number of the crimes that petitioner committed, we are hard pressed to say that his aggregate sentence is constitutionally disproportionate even taking his youth into account. Petitioner killed four people over the course of two days. Additionally, he shot and wounded almost two dozen of his classmates with the intent to kill them. He put a gun to another classmate's head and would have killed him except that the gun ran out of bullets, permitting two students to subdue petitioner before he could shoot anyone else. Finally, even after officers had placed petitioner under arrest, he attempted to kill one of the officers with a knife he had hidden on his person.

**22We recognize, as petitioner and the state argue, that other courts have divided over whether and how Miller and Graham apply to aggregate sentences for multiple crimes. Some courts take the position that the number and nature of a juvenile's crimes are immaterial when an aggregate sentence approximates life without the possibility of parole.17 Others find the existence of an aggregate sentence a sufficient basis, in and of itself, for distinguishing Miller and Graham .18 We strike a middle ground between those two extremes.

*413We note, as an initial matter, that the nature and number of petitioner's crimes in this case distinguish his aggregate sentence from the aggregate sentences that other courts have found inconsistent with Miller and Graham . See note 17 supra . For instance, this is not a case in which petitioner's aggregate life sentence resulted from a single homicide and a subsidiary related offense, such as committing **23murder and possessing the weapon used to commit the murder. See McKinley v. Butler , 809 F.3d 908, 911 (7th Cir. 2016) (considering that circumstance). Nor is it a case in which petitioner's aggregate life sentence resulted solely from nonhomicide offenses. See Moore v. Biter , 725 F.3d 1184, 1192 (9th Cir. 2013) (considering that circumstance). Rather, this is a case in which petitioner's aggregate sentence resulted from four murders and 26 attempted murders, all of which were intentional and each of which inflicted substantial, separate harms on multiple victims.

In the same way that a juvenile who commits a single homicide is subject to a greater sentence than a juvenile who commits a single nonhomicide offense, a juvenile who intentionally commits four murders and 26 attempted murders is subject to a greater sentence "based on both [greater] moral culpability and consequential harm" than a juvenile who commits a single homicide. See Miller , 567 U.S. at 473, 132 S.Ct. 2455 (distinguishing a homicide from a nonhomicide); Solem , 463 U.S. at 293-94, 103 S.Ct. 3001 (explaining that the seriousness of the crimes and the offender's mental state bear on the constitutionally permissible sentence). Additionally, the sentencing court's determination that petitioner should serve 40 months for each classmate whom he shot with the intent to kill reflects a legitimate interest in retribution that is proportionate to each attempted murder and results in a correspondingly proportionate aggregate sentence for all petitioner's crimes. Cf. Roper , 543 U.S. at 571, 125 S.Ct. 1183 (explaining that imposing the death penalty on a juvenile whose culpability is reduced by reason of age is so disproportionate for a single murder that it does not reflect a legitimate penological interest).19

**24It might be possible to uphold petitioner's sentence against an Eighth Amendment challenge based solely on the number and magnitude of his crimes. However, we need not go that far to decide this case: The sentencing court's findings in this case persuade us that petitioner comes within the class of juveniles who, as Miller recognized, may be sentenced to life without possibility of parole for a homicide. As noted, Miller explained that, despite the difficulty "of distinguishing at an early age between 'the juvenile offender whose crime reflects unfortunate yet transient immaturity, and the rare juvenile offender whose crime reflects irreparable corruption,' " the Eighth Amendment permits sentencing a juvenile to life without possibility of parole for a single homicide if that crime reflects irreparable corruption *414rather than the transience of youth. 567 U.S. at 479, 132 S.Ct. 2455 (quoting Roper , 543 U.S. at 573, 125 S.Ct. 1183 ).

The distinction between juveniles whose crime reflects irreparable corruption rather than the transience of youth finds its source in Roper . See Roper , 543 U.S. at 573, 125 S.Ct. 1183 (drawing that distinction). Although Roper announced that distinction without detailing the characteristics that distinguish one class of juvenile offenders from the other, both the discussion that preceded that distinction in Roper and also the Court's decision in Miller shed light on the issue.

As noted above, the Court identified "three general differences" in Roper between juvenile offenders and adults who commit the same offense. Id. at 569, 125 S.Ct. 1183. First, "[a] lack of maturity and an underdeveloped sense of responsibility are found in youth more often than in adults." Id. Second, juveniles are "more vulnerable or susceptible to negative influences or outside pressures." Id. Third, "the personality traits of juveniles are more transitory, less fixed" than adults. Id. at 570, 125 S.Ct. 1183. Each of those characteristics results from a juvenile's age and typically will ameliorate as a juvenile grows older. As the Court put it, " '[t]he relevance of youth as a mitigating factor derives from the fact that the signature qualities of youth are transient; as individuals mature, the impetuousness and recklessness that may dominate in younger years can subside.' " Id. (quoting Johnson , 509 U.S. at 368, 113 S.Ct. 2658 ).

**25It is precisely because the signature qualities of youth are generally transient that a juvenile's commission of a heinous offense usually does not signal an irretrievably depraved character in the same way that an adult's commission of the same offense does. Id. The Court made that point explicitly in Roper :

"The reality that juveniles still struggle to define their identity means it is less supportable to conclude that even a heinous crime committed by a juvenile is evidence of an irretrievably depraved character. From a moral standpoint, it would be misguided to equate the failings of a minor with those of an adult, for a greater possibility exists that a minor's character deficiencies will be reformed."

Id. Put differently, what keeps a juvenile's commission of a heinous offense from reflecting an irretrievably depraved character is the fact that, typically, the characteristics or personality traits that led to the juvenile's commission of the offense are transitory. Conversely, in those rare occasions when those characteristics or traits are fixed, and not transitory, a "heinous crime" can reflect an "irretrievably depraved character" or "irreparable corruption," even when committed by a juvenile.

That conclusion follows from an article that Roper cited in support of the distinction it drew between crimes that reflect the transience of youth and those that reflect irreparable corruption. See id. at 573, 125 S.Ct. 1183 (citing Laurence Steinberg & Elizabeth Scott, Less Guilty by Reason of Adolescence: Developmental Immaturity, Diminished Responsibility, and the Juvenile Death Penalty , 58 Am. Psychologist, 1009, 1014-16 (2003)). In that article, the authors explain that, because most adolescents do not develop a coherent sense of self until late adolescence or early adulthood, their adolescence can be marked by experimentation that involves "risky, illegal, or dangerous activities like alcohol use, drug use, unsafe sex, and antisocial behavior." Steinberg & Scott, 58 Am. Psychologist at 1014. "For most teens, these behaviors are fleeting; they cease with maturity as individual identity becomes settled. Only a relatively small portion of adolescents who experiment in risky or illegal activities develop entrenched patterns of problem behavior that persist into **26adulthood." Id.20 The authors conclude *415that, because most juvenile antisocial behavior does not reflect bad character but instead reflects transient immaturity, juveniles generally should not be subject to the same punishments imposed on adults for the same crimes. Id. at 1015.

The Court's decision in Miller adds one more piece to the puzzle. After observing that the number of juveniles eligible for a life sentence without possibility of parole will be small because of the difficulty of distinguishing between juvenile offenses that reflect the transience of youth and those that reflect irreparable corruption, the Court disagreed with a concern expressed by the dissenting opinions that the Court's holding would preclude "tak[ing] into account the differences among defendants and crimes." Id. at 480 n. 8, 132 S.Ct. 2455. Specifically, the Court made clear that, in deciding whether a juvenile's crime reflects irreparable corruption rather than the transience of youth, sentencing courts can consider that a " '17-year-old [was] convicted of deliberately murdering an innocent victim,' " that a juvenile was convicted of " 'the most heinous murders' " or " 'the worst type of murders,' " or that a " '17-1/2-year-old se[t] off a bomb in a crowded mall.' " Id. (quoting hypotheticals from the dissenting opinions).

As the foregoing discussion makes clear, the transience of youth-the recognition that most juvenile crimes are attributable to traits that will disappear or significantly diminish as a youthful offender ages-is the primary characteristic that justifies a constitutional distinction between the permissible punishment for a juvenile and an adult whose **27crimes are otherwise identical. As Miller explained and Montgomery confirmed, if a single juvenile homicide reflects the transience of youth, the possibility of reformation is too great for life without possibility of parole to be constitutionally permissible. Montgomery , 136 S.Ct. at 734. However, when the traits that led to the commission of the homicide are fixed or irreparable, rather than transient, then that characteristic no longer bars imposition of a life sentence without possibility of parole for a single homicide. Additionally, the homicide must reflect a level of corruption sufficient to impose life without possibility of parole on a juvenile. See Miller , 567 U.S. at 480 n. 8, 132 S.Ct. 2455 (recognizing that the "most heinous murders" or "the worst type of murders" can evidence irreparable corruption even when committed by a juvenile). For example, a single homicide based on a felony murder theory may not justify a sentence of life without the possibility of parole. See id. at 492, 132 S.Ct. 2455 (Breyer, J., concurring) ("The only juveniles who may constitutionally be sentenced to life without parole are those convicted of homicide offenses who 'kill or intend to kill.' ") (Quoting Graham , 560 U.S. at 69, 130 S.Ct. 2011 )).

With that background in mind, we turn to the trial court's findings in this case. As noted, the trial court held a six-day sentencing hearing at which it considered all the evidence that petitioner presented regarding his youth, his psychological problems, and positive aspects of its character. Although the decisions in Roper , Miller , and Montgomery were not available when the trial court sentenced petitioner, the findings that the trial court made bring petitioner within the class of juveniles who, as Miller recognized, may be sentenced to life without possibility of parole.

The trial court accepted, as petitioner's medical experts had testified, that petitioner suffered from a schizoaffective disorder that motivated him to commit his crimes, and the court agreed that petitioner's disorder was not a function of his youth-i.e. , his condition could be treated but never cured. The sentencing court agreed that, if petitioner's disorder were untreated or inadequately treated, petitioner "remained dangerous." Specifically, the sentencing court agreed with petitioner's expert that "there is no *416cure for [petitioner's] condition, that he should never be released without appropriate medication and-I quote-'an awful lot **28of structure and appropriate support services arranged for him.' "21

Those findings are inconsistent with a determination that petitioner's crimes "reflect the transient immaturity of youth." Montgomery , 136 S.Ct. at 734 (summarizing why life without possibility of parole is constitutionally impermissible when applied to most juveniles). Rather, as petitioner's experts testified and the sentencing court found, petitioner's crimes reflect a deep-seated psychological problem that will not diminish as petitioner matures.

We also conclude, and we think no person reasonably could dispute, that petitioner's actions are the sort of heinous crimes that, if committed by an adult, would reflect an "irretrievably depraved character," see Roper , 543 U.S. at 570, 125 S.Ct. 1183, or "irreparable corruption," see Miller , 567 U.S. at 480, 132 S.Ct. 2455. And as Miller recognized, the "most heinous murders" or "worst types of murders," even when committed by a juvenile, can evidence irreparable corruption. 567 U.S. at 480 n. 8, 132 S.Ct. 2455 (internal quotation marks and citation omitted). In this case, petitioner admitted and the trial court found that he intentionally shot his parents: his father as he sat unsuspecting at the kitchen counter and his mother as she came home from an errand. Petitioner admitted and the trial court found that he intentionally killed two classmates: one as he was walking in the school hallway and the other as he was trying to find cover from petitioner's bullets in the school cafeteria. And petitioner shot and wounded nearly two dozen innocent students, some only in the ninth grade, intending to kill each and every one of them.22

**29We recognize that the psychological problems that motivated petitioner's crimes are a two-edged sword. On one hand, the trial court's findings establish that petitioner's crimes stem from fixed psychological problems that will not diminish as petitioner ages. On the other hand, those problems diminish his moral culpability in the same way that any and every defendant whose crimes reflect deep-seated psychological problems can claim diminished moral culpability. However, because petitioner's psychological problems diminish his culpability for reasons that are unrelated to his youth, they are independent of and separate from the concerns that animated the Court's Eighth Amendment holdings in Roper , Miller , and Graham . Put differently, while petitioner's psychological problems are relevant mitigating evidence, which the sentencing court considered, they are not the sort of concerns that led to the categorical sentencing limitations announced in Roper , Miller , and Graham .

The dissenting opinion would reach a different conclusion. As we read the dissent, it turns on two propositions. The dissent rests in large part on the proposition that "petitioner's youth is inextricable from his crimes, and it is difficult to comprehend how petitioner's youth at the time of his crimes, in combination with his mental disorder, did not affect the nature and gravity of his crimes." 363 Or. at 34, 417 P.3d at 419 (Egan, J., dissenting). The dissent also reasons that petitioner's psychological problems reduce his culpability for his crimes in a way that makes life imprisonment without possibility of parole unconstitutional as a matter of federal law. 363 Or. at 38, 417 P.3d at 421 (Egan, J., dissenting).

*417We appreciate the dissent's concerns. However, we question how we can say, as the dissent does, that petitioner's crimes reflect the transience of youth when the trial court reached precisely the opposite conclusion. As noted, the trial court found that "there is no cure for [petitioner's] condition, that he should never be released without appropriate medication and-I quote-'an awful lot of structure and appropriate support services arranged for him.' "23

**30Moreover, given the trial court's finding that the psychological issues that make petitioner dangerous are not transient, we question the other premise on which the dissent rests: the extent to which petitioner's mental health issues bears on the Eighth Amendment analysis in Miller and Montgomery . Unless the Eighth Amendment prohibits imposing a life sentence without the possibility of parole on every criminal defendant (young or old) who commits murder because of psychological issues, we cannot say that it prohibits imposing that sentence on petitioner because he suffers from a psychological problem that will continue throughout his adult years as well as his juvenile ones.24

It is important to remember that the issue before us is limited. The question is not how we would find the facts if we were the sentencing court, nor is the question whether the sentence imposed in this case is the one that we would have imposed if we had sentenced petitioner. Rather, the only question before us is whether the sentence that the trial court did impose falls below federal constitutional standards. Given the trial court's findings and the severity of petitioner's acts, we cannot say that petitioner's sentence is constitutionally disproportionate to his crimes for the reasons that underlie the Court's decisions in Miller and Graham . Because we do not agree with petitioner's argument that the holding and reasoning in Miller render his aggregate sentence unconstitutional under the Eighth **31Amendment, we affirm the Court of Appeals decision and the post-conviction court's judgment.

The decision of the Court of Appeals and the judgment of the circuit court are affirmed.

Egan, J. pro tempore, dissented and filed an opinion.

The majority concludes that the nearly 112-year aggregate sentence imposed on petitioner is permissible because petitioner is "within the class of juveniles who, as Miller [v. Alabama , 567 U.S. 460, 132 S.Ct. 2455, 183 L.Ed. 2d 407 (2012) ] recognized, may be sentenced to life without the possibility of parole." Kinkel v. Persson , 363 Or. 1, 27, 417 P.3d 401, 415 (2018). That exception, as quoted by the majority, is as follows:

"Even if a court considers a child's age before sentencing him or her to a lifetime in prison, that sentence still violates the Eighth Amendment for a child whose crime reflects unfortunate yet transient immaturity. Because Miller determined that sentencing a child to life without parole is excessive for all but the rare juvenile offender whose crime reflects irreparable corruption , it rendered life without *418parole an unconstitutional penalty for a class of defendants because of their status-that is, juvenile offenders whose crimes reflect the transient immaturity of youth."

Montgomery v. Louisiana , --- U.S. ----, 136 S.Ct. 718, 734, 193 L.Ed. 2d 599 (2016) (internal citations and quotation marks omitted; emphasis added). Because the majority's conclusion is based on an incomplete reading of that exception and the mistaken belief that petitioner's youth played no role in his crimes, I dissent.

In Miller , the Supreme Court began with the principle that it had established in Roper v. Simmons , 543 U.S. 551, 125 S.Ct. 1183, 161 L.Ed. 2d 1 (2005) and Graham v. Florida , 560 U.S. 48, 130 S.Ct. 2011, 176 L.Ed. 2d 825 (2010), that "children are constitutionally different from adults for purposes of sentencing." Miller , 567 U.S. at 471, 132 S.Ct. 2455. The Court noted that "developments in psychology and brain science continued to show fundamental differences between juvenile and adult minds" and that "[i]t is increasingly clear that adolescent brains are not yet fully mature in regions and **32systems related to higher-order executive functions such as impulse control, planning ahead, and risk avoidance." Id. at 471-72, 472, 132 S.Ct. 2455 n 5 (internal quotation marks omitted). The Court added that those characteristics-transient rashness, proclivity for risk, and inability to assess consequences-both lessened a child's moral culpability and "enhanced the prospect that, as the years go by and neurological development occurs, his deficiencies will be reformed." Id. at 472, 132 S.Ct. 2455 ((internal quotation marks omitted).

Additionally, in light of those differences, Miller recognized that the distinctive attributes of youth diminish the penological justifications for imposing on child-offenders life sentences without the possibility of release. Id. The case for retribution in sentencing, which is related to an offender's blameworthiness, is weakened when the offender is a juvenile. Id. The deterrence rationale is weakened because the same characteristics that cause juveniles to be less culpable than adults-immaturity, recklessness, and impetuosity-make them less likely to consider potential punishment. Id. The justification for incapacitation is also weakened because ordinary adolescent development reduces the likelihood that a juvenile offender will forever will be a danger to the community. Id. Lastly, the principle of rehabilitation cannot justify the sentence of life without the possibility of release because it necessarily rejects that possibility of reform. Id.

Those considerations form the basis for the Court's holding in Miller that a sentencing court must, before sentencing a juvenile to life without parole, take into account how children are different and how those differences counsel against irrevocably sentencing them to a lifetime in prison. Montgomery , 136 S.Ct. at 733-34. Miller recognized that, in light of children's diminished culpability and heightened capacity for change, it would be "the rare juvenile offender who exhibits such irretrievable depravity that rehabilitation is impossible and life without parole is justified." Montgomery , 136 S.Ct. at 733. That bar is extremely high because life without the possibility of parole, according to the Court, is comparable to the death penalty in terms of severity when applied to a juvenile. See Graham , 560 U.S. at 69-70, 130 S.Ct. 2011.

**33In this case, the majority concludes that petitioner's nearly 112-year sentence is constitutional because his crimes do not "reflect the transient immaturity of youth." 363 Or. at 28, 417 P.3d at 416 (internal quotation marks omitted). The majority arrives at that conclusion based on the testimony at sentencing of petitioner's mental health expert witnesses and majority's inferences from that evidence. Briefly, that testimony was as follows. Petitioner's medical experts, acknowledging that it is difficult to diagnose adolescents, concluded that he suffered from an incurable mental disorder diagnosed as either paranoid schizophrenia or schizoaffective disorder, which combines schizophrenia and depression. For three years prior to his crimes, petitioner had been hearing voices, one of which commanded him to commit the murders and attempted murders. Petitioner's crimes "were directly the product of a psychotic process that had been building intermittently in him over a three-year period"

*419and would not have occurred without petitioner's mental disorder. Although petitioner's mental disorder could not be cured, the experts testified that petitioner's psychosis was treatable with medication and supervision and that he could be a candidate for release. Without treatment, however, petitioner would "remain dangerous." Finally, an expert testified that he would not want to see petitioner out on the streets without medication and a lot of structure and support services arranged for him. The sentencing court adopted that last view in determining petitioner's sentence.

According to the majority, because petitioner's mental disorder caused his crimes and because his mental disorder is not a transient condition, his crimes reflected not "the transient immaturity of youth" but "reflect[ed] instead a deep-seated psychological problem that will not diminish as petitioner matures " and, thus, his nearly 112-year sentence is constitutional. Id . (internal quotation marks omitted). That conclusion disregards two things. First, the acts of petitioner as a child-offender cannot be extricated from the fact that he is a child. And second, to lawfully impose on a child a sentence of life without the possibility of release, Miller requires more than simply a finding that the youth's condition is not transient; it requires also that the crimes show that the child is "irreparabl[y] corrupt[ ]" or "exhibits **34such irretrievable depravity that rehabilitation is impossible and life without parole is justified." Montgomery , 136 S.Ct. at 733-34.

First, I cannot agree that petitioner's crimes do not reflect the transient immaturity of youth. In my view, petitioner's youth is inextricable from his crimes, and it is difficult to comprehend how petitioner's youth at the time of his crimes, in combination with his mental disorder, did not affect the nature and gravity of his crimes. Petitioner's crimes were the result of a set of circumstances that were products of both his age and mental disorder. As a matter of fact, one medical expert testified that it is difficult to diagnose adolescents because of that phenomenon. In Roper , the Court expressed that "[i]t is difficult even for expert psychologists to differentiate between the juvenile offender whose crime reflects unfortunate yet transient immaturity, and the rare juvenile offender whose crime reflects irreparable corruption." 543 U.S. at 573, 125 S.Ct. 1183. That difficulty, according to the Court, "underlies the rule forbidding psychiatrists from diagnosing any patient under 18 as having antisocial personality disorder, a disorder also referred to as psychopathy or sociopathy, and which is characterized by callousness, cynicism, and contempt for the feelings, rights, and suffering of others." Id. (citing American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders 701-06 (4th ed. text rev. 2000)). "If trained psychiatrists with the advantage of clinical testing and observation refrain, despite diagnostic expertise, from assessing any juvenile under 18 as having antisocial personality disorder, we conclude that States should refrain from asking jurors to issue a far graver condemnation[.]" Id.

Petitioner began hearing voices at roughly age 12, three years before his crimes. A child's experience with, and results from, the onset of a mental disorder will almost certainly be different from that of an adult who experiences the onset of the same mental disorder. An adult would more likely be able to understand that something had changed and can better communicate the need for help. A 26-year-old, for example, unlike a 12- to 15-year-old child, who experienced the onset of a mental disorder like petitioner's would have better understood that hearing voices is not simply **35a common part of life for either himself or the majority of other people. And even if a child could understand the significance of hearing voices, the defining characteristics of youth itself make the distinction between the voices and the child's conscience difficult. An adult would be less likely to have allowed the voices to continue without treatment for three years.

Petitioner's expert testified that his crimes "were directly the product of a psychotic process that had been building intermittently in him over a three-year period." (Emphasis added.) An adult faced with the same slow onset would be less likely than a child to allow the build up to continue until a crisis point that left four people dead and tens *420more injured or otherwise harmed. Finally, an adult, who has had the benefits of a diagnosis, medication, behavioral treatment, and time to allow for maturity of understanding those things does not have the same danger as an untreated child. For those reasons, I disagree that petitioner's mental disorder was solely, to the exclusion of any role of petitioner's youth, responsible for his crimes.

Second, and relatedly, I disagree with the majority's conclusion that a child may be sentenced to life without the possibility of release based solely on the determination that petitioner's crimes do not "reflect the transient immaturity of youth." As I noted, I believe that the majority's conclusion is based on an incomplete reading of what Miller requires. As summarized by the Supreme Court in Montgomery :

" Miller required that sentencing courts consider a child's diminished culpability and heightened capacity for change before condemning him or her to die in prison. Although Miller did not foreclose a sentencer's ability to impose life without parole on a juvenile, the Court explained that a lifetime in prison is a disproportionate sentence for all but the rarest of children, those whose crimes reflect irreparable corruption."

136 S.Ct. at 726 (internal citations and quotation marks omitted).

Petitioner's crimes do not reflect irreparable corruption and do not exhibit such irretrievable depravity that life in prison without the possibility of release is constitutionally **36justified. There is no question that petitioner's crimes were horrendous. Any legal conclusion about petitioner or his sentence does not require this, or any, court to diminish or ignore the immense pain, suffering, and loss of life that petitioner inflicted. Petitioner killed four people. He attempted to kill 26 more people. His crimes took place over a period of less than 24 hours. His crimes were the heartbreaking culmination of three years of intermittently building psychosis. His crimes were the product of a 15-year-old boy with a mental disorder. In total, those statements do not demonstrate irreparable corruption. Rather, they demonstrate a brief but horrible psychotic break with horrific consequences.

There is no evidence admitted for the truth of the matter asserted that petitioner's crimes are the result of an irretrievable depravity.1 There is no evidence that petitioner had engaged in a pattern or series of crimes that would demonstrate that he can never be trusted to be free within the community without causing harm or otherwise committing crimes. The majority assumes that it is implicit in the sentencing court's findings that the number and magnitude of petitioner's crimes reflect a disregard for human life that requires that petitioner serve a 70-month minimum sentence, with 40 months consecutive for each of the 26 persons whom he intended to kill. But that only follows if the petitioner is fully culpable for his crimes. The rarest of children whose crimes reflect irreparable corruption are the cool and calculated souls who appreciate and understand their conditions and who either use the conditions as a means to an end or who revel in the hideousness of their depravity. The rarest of children are not those who struggle with their disorder and fail. Petitioner, as a 12- to 15-year old child, heard voices as a result of his mental disorder for three years prior to his crimes, including one voice that told him to kill. Petitioner's crimes "were directly the product of a psychotic process that had been building intermittently in him over a three-year period" and would not have occurred without petitioner's mental disorder. There is no evidence that petitioner had a disregard for human life before his crimes or **37that he retained a disregard for human life past the time of his crimes.

Instead, the evidence supports a conclusion that that disregard for human life was a temporary product of petitioner's mental disorder. The conditional statements made by the expert witnesses that petitioner would remain dangerous if he did not accept treatment also mean that petitioner would not be *421dangerous unless he did not receive treatment for his mental disorder. Therefore, the danger-the risk produced from a disregard for human life-can also be treated. If there is evidence that the condition causing his dangerousness or corruption can be treated, then that corruption is conditional and cannot be considered irreparable. The fear of the danger of petitioner without treatment does not allow for a determination that he is irreparably corrupt when the expert testimony resoundingly supported the idea that petitioner can be safely released under certain circumstances.

The onerous and disproportionately severe sentencing of child offenders with treatable mental illness that manifest in terrible criminal acts tends to drive the public narrative in the wrong direction. When the highest court in the land validates such a sentence, the harm is much greater than the alternative of treatment and release of schizophrenic youths who commit these crimes. That greater harm comes when courts reinforce notions about mental illness in relation to mass shootings that reflect larger cultural stereotypes and public anxieties about matters such as race, ethnicity, social class, and politics.2 We obscure the issue of race, ethnicity, social class, and politics when we allow mass shootings to represent all gun crime and when we stop using "mental illness" as a medical diagnosis and change it into a sign of gun violence.3 The facts surrounding this particular mass shooting are well known and irrefutable.

The facts about mental illness are now common knowledge and irrefutable as well. One in five Americans **38experience some detectable measure of mental illness in a given year; one in 25 American adults experience a serious mental illness in a given year; and one in five American youths ages 13 to 18 experience a severe mental illness.4 These numbers illustrate the fact that children with severe mental illness mature, and become law abiding adults. The largest share of adults with mental illness live without any limitations in their activities of daily living. Only a small fraction of severely mentally ill youths become severely mentally ill adults. The principles that the Court relied on in Miller cannot allow a conclusion that it is acceptable to imprison for the entirety of their lives any of these youth offenders whose mental illness will likely result in treatable conditions in adulthood without some manifestation of irreparable corruption. In doing so, we buy in to the narrative that the problem is mental illness.

The Court in Miller noted that, given all it said in Roper and Graham , imposition of the harshest penalty possible for a child, life without the possibility of release, will rarely be constitutional because of the great difficulty of determining that a child's crimes reflect irreparable corruption. Miller , 567 U.S. at 479, 132 S.Ct. 2455. That holds true in this case. A conclusion that petitioner's crimes reflect irreparable corruption requires a determination that the danger that petitioner poses to the community will not end or change and cannot be forecast to end or change such that the state is justified in incapacitating him and the threat he poses until his death. Petitioner's crimes reflect a danger that can be reduced and changed-it is neither a certainty nor a constant that the danger petitioner posed at sentencing will not end.

Petitioner's crimes were absolutely horrific. Those crimes were committed by a child with a treatable mental disorder. They do not show irreparable corruption. Both his age and his mental disorder reduce his moral culpability. And both his age and the fact that his mental disorder is treatable weigh against both an explicitly retributive *422**39sentence and a sentence aimed at incapacitating him for the rest of his life.

In sum, because I believe that petitioner's crimes are the horrible acts of a juvenile offender whose crimes reflect an unfortunate yet transient immaturity, and because I believe that he is not the rare juvenile offender whose crimes reflect irreparable corruption, I would hold that petitioner's nearly 112-year sentence of incarceration is unconstitutional.

I respectfully dissent.