1 (Slip Opinion) OCTOBER TERM, 2023

Syllabus

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is being done in connection with this case, at the time the opinion is issued. The syllabus constitutes no part of the opinion of the Court but has been prepared by the Reporter of Decisions for the convenience of the reader. See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337. 

## SUPREME COURT OF THE UNITED STATES

Syllabus

THORNELL, DIRECTOR, ARIZONA DEPARTMENT OF CORRECTIONS v . JONES

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT

No. 22–982. Argued April 17, 2024—Decided May 30, 2024
Respondent Danny Lee Jones was conv icted of the premeditated firstdegree murders of Robert and Tisha Weaver and the attempted pre

meditated murder of Robert’s grandmother Katherine Gumina. Ari

zona law at the time required the trial court to “impose a sentence of death” if it found “one or more” statutorily enumerated “aggravating circumstances” and “no mitigating circumstances sufficiently substan

tial to call for leniency.” Ariz. Rev. Stat. Ann. §13–703(E). The trial court found three aggravating circumstances that applied to both Rob

ert’s and Tisha’s murders: Jones committed multiple homicides, §13– 703(F)(8); he was motivated by “pecuniary” gain, §13–703(F)(5); and the murders were “especially hein ous, cruel or depraved,” §13– 703(F)(6). The trial court found an additional aggravating circum

stance with respect to Tisha’s murder: she was a young child, §13– 703(F)(9). The trial court also concluded that Jones had established four mitigating circumstances: long-term substance abuse, drug and alcohol impairment at the time of the murders, head trauma, and childhood abuse. 9 Record 2465. The court concluded that these miti

gating circumstances were “not sufficiently substantial to outweigh the aggravating circumstances,” so it sentenced Jones to death. Ibid

. The Arizona Supreme Court affirmed after “review[ing] the entire rec

ord” and “independently weighing all of the aggravating and mitigat

ing evidence presented.” 185 Ariz. 471, 492, 917 P. 2d 200, 221.

Jones later sought state postconvic tion review on th e theory that de

fense counsel was ineffective, but th e Arizona courts rejected Jones’s claims. Jones next filed a federal habeas petition in District Court and reasserted his ineffective-assistance -of-counsel claims. The District Court held an evidentiary hearing bu t ultimately concluded that Jones2 THORNELL v. JONES

Syllabus

could not show prejudice because th e additional information he pre

sented “ ‘barely. . . alter[ed] the sentenci ng profile presented to the sen

tencing judge.’ ” Jones v. Schriro , 450 F. Supp. 2d 1023, 1043 (quoting Strickland v. Washington , 466 U. S. 668, 700). The Ninth Circuit re

versed, but this Court vacated that judgment and remanded for the Ninth Circuit to determine whether, in light of Cullen v. Pinholster

, 563 U. S. 170, it had been proper to consider the new evidence pre

sented at the federal ev identiary hearing. See Ryan v. Jones , 563 U. S. 932. On reconsideration, the Ninth Circuit again granted habeas re

lief. The panel held that it was permissible to consider the new evi

dence and concluded that there was a “ ‘reasonable probability’ ” that “Jones would not have received a de ath sentence” if that evidence had been presented at sentencing. Jones v. Ryan , 52 F. 4th 1104, 1137. Ten judges dissented from the denial of en banc review. One dissent, joined by eight judges, asserted th at the Ninth Circuit panel flouted Strickland by crediting “questionable, weak, and cumulative mitiga

tion evidence” as “enough to overco me . . . weight[y] . . . aggravating circumstances.” Id. , at 1155.
Held : The Ninth Circuit’s interpre tation and application of Strickland

was in error

. Pp. 7–16. (a) To succeed on his ineffective- assistance-of-counsel claim, Jones must show that counsel provided a “deficient” performance that “prej

udiced” him. Strickland , 466 U. S., at 687. Jones can show prejudice only if “there is a reasonable probability that, absent [counsel’s] errors, the sentencer . . . would have concluded that the balance of aggravat

ing and mitigating circumstances did not warrant death.” Id ., at 695. “A reasonable probability is a probability sufficient to undermine con

fidence in the outcome. That requir es a substantial, not just conceiv

able, likelihood of a different result.” Pinholster , 563 U. S., at 189 (ci

tation and internal quotation mark s omitted). To determine whether a prisoner satisfies this standard, a court must “consider the totality of the evidence before the judge or jury”—both mitigating and aggra

vating. Strickland , 466 U. S., at 695.

The Ninth Circuit departed from these well-established rules in at least three ways. First, it failed ad equately to take into account the weighty aggravating circumstances. Second, it applied a strange Cir

cuit rule that proh ibits a court in a Strickland case from assessing the relative strength of expert witness te stimony. Third, it held that the District Court erred by attaching diminished persuasive value to Jones’s mental health conditions. See 52 F. 4th, at 1129. Contrary to the Ninth Circuit’s suggestion, Eddings v . Oklahoma , 455 U. S. 104, permits a sentencer to find mitigating evidence unpersuasive.

Jones argues that a habeas petitioner is entitled to relief whenever he or she “presents substantial evid ence of the kind that a reasonable3 Cite as: 602 U. S. ____ (2024)

Syllabus

sentencer might deem relevant to the defendant’s moral culpability.” Brief for Respondent 14. This rule is squarely at odds with the estab

lished understanding of prejudice under Strickland , which requires a “reasonable probability” of a different result. Where aggravating fac

tors greatly outweigh mitigating evidence, there may be no “reasona

ble probability” of a different result. Pp. 7–9.

(b) Turning to the issue of prejudice in this case, the mitigating evi

dence Jones presented at the fede ral evidentiary hearing “would barely have altered the sentencing pr ofile presented to the sentencing judge,” and it is insuffici ent to show prejudice. Strickland , 466 U. S., at 700. Pp. 9–13. (1) Jones presented evidence th at, he claims, shows he suffers from various mental illnesses. But Arizona courts had already heard testimony that Jones “suffers from a major mental illness,” likely a “form of Bipolar Affective Disorder.” 4 Record 1070; 10 id ., at 2567. And they declined to give this evid ence much weight because Jones did not “establish a causal connection between his alleged mental illness and his conduct on the night of the murders.” 185 Ariz., at 492, 917 P. 2d, at 221. Jones’s new evidence did not fix that problem because Jones’s experts provided no real link between Jones’s disorders and the murders. Pp. 9–10. (2) Next, Jones introduced eviden ce that he suffers from cognitive impairment caused by physical trauma that he suffered during his mother’s pregnancy, at birth, and la ter in life. But Arizona courts had already heard extensive evidence about Jones’s head trauma and cog

nitive impairment and did not find this evidence sufficient to warrant leniency. Ibid. The little evidence Jone s added at his evidentiary hearing at most corroborates the te stimony that the Arizona courts already credited, and it would thus provide little benefit. Pp. 11. (3) In federal court, Jones also alleged sexual abuse by his grand

father and physical abuse by his seco nd stepfather. But this evidence would not help either. Again, the Arizona courts had heard about many other instances of childhood abuse but concluded they did not warrant leniency, primarily because the abuse appeared unconnected to the murders. 185 Ariz., at 490–491, 917 P. 2d, at 219–220; 9 Record 2465. The new allegations are lik ewise not causally connected and, at any rate, are uncorroborated. Ariz ona courts would give such selfreported and uncorroborated evidence “little . . . mitigating weight.” State v. Sharp , 193 Ariz. 414, 425, 973 P. 2d 1171, 1182. Pp. 12–13. (4) Finally, Jones produced evid ence of substance abuse, but his history of substance abuse was “well-documented” at the time of sen

tencing, and the Arizona Supreme Court gave this fact “some mitigat

ing weight,” 185 Ariz., at 491, 917 P. 2d, at 220. There is no reasonable chance Arizona courts would reach a different result on essentially the4 THORNELL v. JONES

Syllabus

same evidence. P. 13.

(c) The weakness of Jones’s mitigating evidence contrasts sharply with the strength of the aggrav ating circumstances. These circum

stances—multiple homicides, cruel ty, pecuniary motivation, and mur

der of a child—are given great weig ht in Arizona. The Arizona Su

preme Court has repeatedly held that one or more of these aggravating circumstances outweighed mitigati on evidence—even evidence that was “not insubstantial.” State v. Hampton , 213 Ariz. 167, 185, 140 P. 3d 950, 968. Conversely, Jones and his amici identify no cases in which the Arizona Supreme Court has vacated the judgment of death in a case involving multiple murder s—let alone all of the aggravating circumstances present here. The absence of such a case strongly sug

gests that Jones has no reasonable probability of escaping the death penalty. Pp. 13–14.

(d) Contrary to the Ninth Circuit’s conclusion, “the Strickland prej

udice analysis conducted by the Supreme Court” in other cases, 52 F. 4th, at 1131, does not support resentencing here. In those cases, defense counsel introduced little, if any, mitigating evidence at the original sentencing, and the aggravating circumstances were weaker. By contrast, Jones started with much more mitigation evidence, and the aggravating circumstances present here are weightier. Had the Ninth Circuit engaged in th e analysis required by Strickland , it would have affirmed the decision of the Di strict Court denying habeas relief. Pp. 14–16. 52 F. 4th 1104, reversed and remanded.

A LITO , J., delivered the opinion of the Court, in which R OBERTS , C. J., and T HOMAS , G ORSUCH , K AVANAUGH , and B ARRETT , JJ., joined. S O

TOMAYOR , J., filed a dissenting opinion, in which K AGAN , J., joined. J ACK

SON , J., filed a dissenting opinion._________________

_________________ 1 Cite as: 602 U. S. ____ (2024)

Opinion of the Court

NOTICE: This opinion is subject to formal revision before publication in the United States Reports. Readers are requested to notify the Reporter of Decisions, Supreme Court of the Unit ed States, Washingt on, D. C. 20543, pio@supremecourt.gov , of any typographical or other formal errors. 

## SUPREME COURT OF THE UNITED STATES

No. 22–982

RYAN THORNELL, DIRECTOR, ARIZONA DEPARTMENT OF CORRECTIONS, PETITIONER v . DANNY LEE JONES

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT
[May 30, 2024]

J USTICE A LITO delivered the opinion of the Court. In this case, we review a de cision of the Ninth Circuit or

dering the resentencing of a defendant who, in order to steal a gun collection, committed thr ee gruesome killings, includ

ing the cold-blooded murder of a 7-year-old girl. The Ninth Circuit held that the defendant’s Sixth Amendment right to the effective assistance of counsel was violated during the sentencing phase of his capital trial. In reaching this con

clusion, the Ninth Circuit s ubstantially departed from the well-established standard articulated by this Court in Strickland v. Washington , 466 U. S. 668 (1984). Among other things, the Ninth Circuit all but ignored the strong aggravating circumstances in this case. As a result, we must reverse the judgment below.

I A Thirty-two years ago, Danny Lee Jones murdered Robert Weaver, his 7-year-old daug hter Tisha Weaver, and his grandmother Katherine Gumina. Jones knew that Robert2 THORNELL v. JONES

Opinion of the Court owned a $2,000 gun collection, and after spending a day drinking and talking with Robert, Jones decided he wanted to steal the guns. He grabbed a baseball bat, beat Robert into unconsciousness, and headed indoors to find the collec

tion. Once inside, Jones encountered Gumina, who was watch

ing television, and Tisha, who was coloring in a workbook before heading to bed. Jones struck Gumina hard enough to crack her skull, leaving her unconscious on the living room floor. Tisha apparently watched Jones attack her great-grandmother and ran to hide under her parents’ bed. Marks on the carpet show that Jones dragged the girl out from under the bed before beating her hard enough “to cre

ate a wound several inches wi de, extending from her left ear to her left cheek.” State v. Jones , 185 Ariz. 471, 489, 917 P. 2d 200, 218 (1996). Jones then asphyxiated Tisha with a pillow. Jones next began loading Robert’s guns into Gumina’s car. At that point, Robert re gained consciousness. “Blood smears at the scene showed that [Robert] attempted to run from” Jones, but Jones “struck [him] in the head several more times. The last blow . . . was delivered while [Robert] knelt helplessly on the floor of the garage.” 9 Appellant’s Excerpts of Record in No. 18–99005 (CA9), p. 2449 (Record). Jones then skipped town with the guns, using them to pay for a trip to Las Vegas. A short time later, Robert’s wife came home from work and discovered the gruesome scene. She called 911, but the first responders found that Ro bert and Tisha were already dead. Gumina lived for 17 months before succumbing to her injuries. Before Gumina died, Jones was charged with two counts of premeditated first-degree murder and one count of attempted premeditated first-degree murder, and a jury found him guilty on all three charges. 1

——————

1 Arizona charged Jones before Gumina’s death and elected not to3 Cite as: 602 U. S. ____ (2024)

Opinion of the Court

B After Jones was convicted, the trial court proceeded to sentencing. Under Arizona law at the time, the court was required to “impose a sentence of death” if it found “one or more” statutorily enumerated “aggravating circumstances” and “no mitigating circumstances sufficiently substantial to call for leniency.” Ariz. Rev. Stat. Ann. §13–703(E) (1993). The trial court found three aggravating circumstances that applied to both Robert’s and Tisha’s murders. First, Jones committed multiple ho micides “during the commis

sion of the offense.” §13–703(F)(8). Second, he was moti

vated by “pecuniary” gain, namely, Robert’s guns. §13– 703(F)(5). And third, the murders were “especially heinous, cruel or depraved.” §13–703(F)(6). With respect to Tisha’s murder, the court found an additional aggravating circum

stance: She was a young child. §13–703(F)(9). The trial court also heard mitigating evidence. The presentence report noted that Jones was abused as a child, began using drugs and alcohol at age 13, suffered brain trauma at ages 9 and 18, and had received “psychiatric treatments” as a child. 4 Record 1086–1088. Jones’s second stepfather, Randy, described Jones’s troubled personal life. He testified that Jones’s father and first stepfather were physically abusive, that Jone s’s grandfather and uncle had introduced him to drugs as a preteen, and that Jones had suffered several head injuries that left him with “con

stan[t]” headaches. 9 id ., at 2522–2526. Jones’s counsel also submitted a report by and solicited testimony from Dr. Jack Potts, a court-appointed forensic psychiatrist who was later de scribed by counsel as essen

tially “part of the defense team.” 7 id ., at 1831. Dr. Potts identified several “mitigating factors” that he thought war

ranted leniency. 4 id ., at 1070–1071. First, he noted that Jones “was reared in a chaoti c and at times grossly hostile

—————— amend the indictment after she died.4 THORNELL v. JONES

Opinion of the Court environment where physical abuse was too prevalent.” Id

., at 1069. “The years he had of a relatively ‘normal’ child

hood,” Dr. Potts opined, were “too late . . . to counter the earlier abuse.” Id ., at 1070. Second, Dr. Potts suggested that Jones’s “serious head trauma” potentially “con

tribut[ed] to his behavior.” Id ., at 1068, 1071. Third, he concluded with a “reasonable degree of medical certainty” that Jones “suffers from a major mental illness,” likely a “form of Bipolar Affective Disorder.” Id ., at 1070; 10 id ., at 2567. Fourth, he thought Jones was “genetic[ally]” predis

posed to “substance abuse” and speculated that Jones would not have murdered had he been sober. 4 id ., at 1070. Fifth, Dr. Potts believed that Jones felt “remorse and re

sponsibility” and that he had the “potential for rehabilita

tion.” Id ., at 1070–1071. From this evidence, the trial court concluded that Jones had established four mitigating circumstances: (1) Jones suffered from long-term substance abuse; (2) that problem may be caused by genetic factors and head trauma; (3) he was under the influence of alcohol and drugs at the time of the murders; and (4) he was abused as a child. 9 id ., at 2465. The court concluded that these circumstances were “not sufficiently substantial to outweigh the aggravating circumstances,” so it sentenced Jones to death. Ibid. The Arizona Supreme Court affirmed after “review[ing] the en

tire record” and “independently weighing all of the aggra

vating and mitigating evidence presented.” Jones , 185 Ariz., at 492, 917 P. 2d, at 221.

C Jones sought state postconviction review on the theory that defense counsel was ineffective. Jones argued that his attorney should have retained an independent neuropsy

chologist, rather than relying on Dr. Potts. The state court denied this claim because it “remember[ed]” that Dr. Potts “was a very good expert” at trial and “was defense oriented.”5 Cite as: 602 U. S. ____ (2024)

Opinion of the Court

7 Record 1950. Jones also claimed that trial counsel failed to make a timely request for neurological or neuropsycho

logical testing. But after hold ing an evidentiary hearing on this claim, the state court rejected it on the merits. Jones then unsuccessfully sought review in the Arizona Supreme Court. Order in State v. Jones , No. CR–00–0512–PC (Feb. 15, 2001); 1 Record 186.

D

Jones next filed a habeas pe tition in Federal District Court and reasserted his ine ffective-assistance-of-counsel claims. See 28 U. S. C. §2254. The District Court held an evidentiary hearing but ultimately concluded that Jones could not show prejudice because the additional infor

mation he presented “ ‘barely . . . alter[ed] the sentencing profile presented to the sentencing judge.’ ” Jones v. Schriro , 450 F. Supp. 2d 1023, 1043 (Ariz. 2006) (quoting Strickland , 466 U. S., at 700). The court reached this con

clusion based on its assessment of “the credibility of the parties’ witnesses,” including witnesses introduced by the State to undercut Jones’s claims. 450 F. Supp. 2d, at 1038. The Ninth Circuit reversed. See Jones v. Ryan , 583 F. 3d 626 (2009). But this Court vacated that judgment and re

manded for the Ninth Circuit to determine whether, in light of Cullen v. Pinholster , 563 U. S. 170 (2011), it had been proper to consider the new evidence presented at the fed

eral evidentiary hearing. See Ryan v. Jones , 563 U. S. 932 (2011). On reconsideration, the Ninth Circuit again granted ha

beas relief. The panel held that it was permissible to con

sider the new evidence 2 and concluded that there was a

——————

2 The panel reasoned that the post conviction review court had not reached the issue of prejudice, so it could review the issue de novo . Fur

ther, “Jones satisfied the standard for an evidentiary hearing pursuant to §2254(e)(2)” because he “exercised diligence in pursuing [his] claims in state court.” Jones v. Ryan , 52 F. 4th 1104, 1123 (CA9 2022). Arizona6 THORNELL v. JONES

Opinion of the Court “reasonable probability” that “Jones would not have re

ceived a death sentence” if that evidence had been pre

sented at sentencing. Jones v. Ryan , 1 F. 4th 1179, 1196, 1204 (CA9 2021). The panel’s lengthy opinion made no mention of the aggravating factors, and it did not consider the State’s rebuttal evidence. Arizona sought en banc review. The Ninth Circuit denied the State’s petition, but the panel amended its opinion to mention the aggravating circumstances and to rebuke the District Court for “weigh[ing] the testimony of [competing] experts against each other.” Jones v. Ryan , 52 F. 4th 1104, 1128 (2022). Ten judges dissented from the denial of en banc review. Judge Ikuta, joined by two ot her judges, argued that the panel should have deferred to the state postconviction re

view court on the Strickland prejudice inquiry. Judge Ben

nett, joined by eight others, assumed without deciding that the panel could consider the new evidence. But he asserted that the panel flouted Strickland by crediting “questiona

ble, weak, and cumulative mitigation evidence” as “enough to overcome . . . weight[y] . . . aggravating circumstances.” 52 F. 4th, at 1155 (dissenting opinion). If not corrected, Judge Bennett wrote, the panel’s errors would enable “courts to improperly grant se ntencing relief to capital de

fendants who have been convicted of the most horrific crimes.” Id ., at 1137. We granted certiorari to review the Ninth Circuit’s inter

pretation and application of Strickland. 601 U. S. ___ (2023).

—————— does not challenge either determinatio n. See Tr. of Oral Arg. 22; Brief for Petitioner 20, n. 8. So we do not decide whether the Ninth Circuit’s interpretation of either the postconv iction review court’s decision or §2254(e)(2) is correct.7 Cite as: 602 U. S. ____ (2024)

Opinion of the Court

II Jones claims that his Sixth Amendment right to the ef

fective assistance of counsel was violated during the sen

tencing phase of his capital trial. To succeed on such a claim, a defendant must show that counsel provided a “de

ficient” performance that “prejudiced” him. Strickland , 466 U. S., at 687. When an ineffective-assistance-of-counsel claim is based on counsel’s performance at the sentencing phase of a capital case, a defendant is prejudiced only if “there is a reasonable probability that, absent [counsel’s] errors, the sentencer . . . would have concluded that the bal

ance of aggravating and mitigating circumstances did not warrant death.” Id ., at 695. “A reasonable probability is a probability sufficient to undermine confidence in the out

come. That requires a substantial, not just conceivable, likelihood of a different result.” Pinholster , 563 U. S., at 189 (citation and internal quotation marks omitted). This standard does not require a defendant to show that it is more likely than not that adequate representation would have led to a better result, but “[t]he difference” should matter “only in the rarest case.” Strickland , 466 U. S., at 697. To determine whether a prisoner satisfies this stand

ard, a court must “consider the totality of the evidence be

fore the judge or jury”—both mitigating and aggravating. Id ., at 695. The Ninth Circuit departed from these well-established rules in at least three ways. First, it failed adequately to take into account the weighty aggravating circumstances in this case. As noted, the panel’s initial opinion did not men

tion those circumstances at all. After the State petitioned for rehearing and 10 judges voted to grant the petition, the panel issued an amended opinion that at least mentioned the aggravating circumstances, but it failed to give them the weight that they would almo st certainly be accorded by an Arizona sentencing judge. Second, the Ninth Circuit applied a strange Circuit rule8 THORNELL v. JONES

Opinion of the Court
that prohibits a court in a Strickland case from assessing the relative strength of expe rt witness testimony. See 52 F. 4th, at 1128–1129. This rule is clearly unsound. Deter

mining whether a defense expert’s report or testimony would have created a reasonable probability of a different result if it had been offered at trial necessarily requires an evaluation of the strength of t hat report or testimony. And where a prosecution expert has expressed a contrary opin

ion, it is hard to see how a court could decide how much weight to give the defense ex pert without making a compar

ative analysis. Third, the Ninth Circuit held that the District Court erred by attaching diminished persuasive value to Jones’s mental health conditions bec ause it saw no link between those conditions and Jones’s conduct when he committed the three murders. See id. , at 1129. The Ninth Circuit seemed to suggest that this conclusion was supported by Eddings v. Oklahoma , 455 U. S. 104 (1982), but that is not

so. Eddings held that a sentencer may not “refuse to con

sider . . . any relevant mitigating evidence.” Id ., at 114

. It did not hold that a sentence r cannot find mitigating evi

dence unpersuasive. See id ., at 114–115 (emphasizing that “[t]he sentencer . . . may dete rmine the weight to be given relevant mitigating evidence”). Picking up what he takes to be the implications of these three features of the Ninth Circuit’s analysis, Jones argues that a habeas petitioner is entitled to relief whenever he or she “presents substantial evidence of the kind that a rea

sonable sentencer might deem re levant to the defendant’s moral culpability.” Brief for Respondent 14. Whether or not this rule represents a fair extrapolation of the Ninth Circuit’s reasoning, it is squarely at odds with the estab

lished understanding of prejudice, which requires a “rea

sonable probability” of a different result. Imagine a defend

ant with the worst possible aggravating circumstances, say,9 Cite as: 602 U. S. ____ (2024)

Opinion of the Court multiple, vulnerable victims; torture; a lengthy record of vi

olent crime; no remorse; and a vow to kill again if given the chance. According to Jones, if the defense is able to show that trial counsel failed to pr oduce any mitigating evidence that can be characterized as “substantial,” the defendant must be resentenced. But in such a case, where the aggra

vating factors greatly outweigh the mitigating evidence, there may be no “reasonable probability” of a different re

sult. Thus, Jones’s argument is squarely inconsistent with Strickland

. III With the proper understanding of Strickland in mind, we turn to the prejudice issue in this case. Most of the mitigat

ing evidence Jones presented at the federal evidentiary hearing was not new, and w hat was new would not carry much weight in Arizona courts. Conversely, the aggravat

ing factors present here are extremely weighty. As a result, there is no reasonable probability that the evidence on which Jones relies would have altered the outcome at sen

tencing.

A We begin with the mitigating evidence. In the District Court, Jones introduced evidence of (1) mental illness, (2) cognitive impairment caused by a history of head trauma, (3) childhood abuse, and (4) substance abuse. Jones claims that this evidence requires resentencing, but as the District Court aptly observed, this evidence “would barely have altered the sentencing profile presented to the sentencing judge,” and it is insufficient to show prejudice. Strickland , 466 U. S., at 699–700.

1
Jones claims that his newl y proffered evidence shows that he suffers from “PTSD, AD/HD, mood disorder, [and] bipolar depressive disorder.” Brief for Respondent 45. But10 THORNELL v. JONES

Opinion of the Court
it is not reasonably likely that this evidence would have re

sulted in a different sentence. Arizona courts had already re ceived testimony that Jones “suffers from a major mental illness,” likely a “form of Bi

polar Affective Disorder.” 4 Record 1070; 10 id ., at 2567. Yet they declined to give this evidence much weight because Jones did not “establish a causal connection between his al

leged mental illness and his conduct on the night of the murders.” Jones , 185 Ariz., at 492, 917 P. 2d, at 221; accord, State v. Prince , 226 Ariz. 516, 542, 250 P. 3d 1145, 1171 (2011) (discounting poor mental health when no “expert could establish [the defendant’s] mental state on the night of the shootings”); State v. Boggs , 218 Ariz. 325, 343, 185 P. 3d 111, 129 (2008) (same). Jones’s new evidence did not fix that problem. One of Jones’s experts reiterated that Jones has a mood disorder, but he did not express an opinion on whether that disorder affected Jones on the night of the murders. 4 Record 823– 825. Two experts diagnosed Jones with PTSD, but neither testified that he experienced such symptoms at the time of the murders. 2 id ., at 506–508; id ., at 451–453. Likewise, no expert linked Jones’s AD/HD to the murders; indeed, one of the State’s witnesses testified that there is no link be

tween that disorder and violence. Id ., at 459. Because none of Jones’s experts provided a real link between Jones’s dis

orders and the murders, their testimony would have done him little good in the Arizona courts. See State v. Poyson

, 250 Ariz. 48, 53, 58, 475 P. 3d 293, 298, 303 (2020) (failure to link mitigating evidence to the crime may diminish its weight); State v. Stuard , 176 Ariz. 589, 608, n. 12, 863 P. 2d 881, 900, n. 12 (1993) (“[E]vidence of causation is required before mental impairment can be considered a significant mitigating factor”).11 Cite as: 602 U. S. ____ (2024)

Opinion of the Court

2 Next, Jones introduced evidence that he suffers from cog

nitive impairment caused by physical trauma that he suf

fered during his mother’s pregnancy, at birth, and later in life. Brief for Respondent 44. But there is no reason to think that this evidence wo uld have meaningfully changed how the state court viewed the case. Arizona courts had already heard extensive evidence about Jones’s head trauma and cognitive impairment. For instance, the sentencing court learned that Jones’s biologi

cal father knocked his mother down stairs when she was pregnant with him, 4 Record 1067, 9 id ., 2523, that his birth was traumatic, ibid. , and that he was physically abused by his first stepfather, 4 id ., at 1067. The sentencing court knew that Jones had been knocked unconscious as the re

sult of three falls during childhood and adolescence and a mugging in his late teens. Id ., at 1068, 1087; 9 id ., at 2526, 2528–2529; 10 id ., at 2556–2557, 2569, 2580. It also heard from Dr. Potts that Jones’s head trauma potentially con

tributed to his behavior. 4 id ., at 1068, 1071. Yet it did not find this evidence sufficient to warrant leniency. And after reviewing the same evidence, the Arizona Supreme Court concurred. Jones , 185 Ariz., at 492, 917 P. 2d, at 221 (cred

iting Dr. Potts’s assumption that Jones had brain damage). Jones added little on this issue at his evidentiary hearing. He alleged a few additional head injuries from car accidents and fights, but “there is no medical documentation to cor

roborate any of these injuries.” Jones , 450 F. Supp. 2d, at 1039, and n. 11. And though his experts flagged a handful of poor test scores and grad es, Jones’s IQ and standardized test scores are mostly average. 2 Record 347, 358–376, 379– 399; 3 id ., at 798. This vague evidence at most “corrobo

rate[s]” testimony the Arizo na courts already credited. Jones , 185 Ariz., at 492, 917 P. 2d, at 221. Introducing it “would have offered an insignificant benefit, if any at all.” Wong v. Belmontes , 558 U. S. 15, 23 (2009) ( per curiam ).12 THORNELL v. JONES

Opinion of the Court

3 Jones also alleges significant childhood abuse. Brief for Respondent 44. Again, however, Arizona courts had heard much on this topic. They knew that Jones’s father abused his pregnant mother, that his first stepfather beat both of them, and that his grandfather introduced him to drugs at a young age. And they received testimony that any period of normalcy during Jones’s childhood was “too late” and “not strong enough to counter the earlier abuse.” 4 Record 1069–1070. They nevertheless concluded that this abuse did not warrant leniency, primarily because it appeared un

connected to the murders. Jones , 185 Ariz., at 490–491, 917 P. 2d, at 219–220; 9 Record 2465. In federal court, Jones added two new allegations. First, he asserted that the grandfather who introduced him to al

cohol also sexually abused him. Second, he claimed that his second stepfather, Randy, physic ally abused him. It is not likely that these allegations would have moved the state court either. The sexual-abuse allegation is entirely uncorroborated. Jones did not mention it until his federal habeas proceed

ings. 2 id. , at 503–504. And his mother and second stepfa

ther explained that they “never saw any indication that [Jones] may have been sexually abused by anyone, nor were they aware of any sexual perpetrators in the family.” Rec

ord in No. 2:01–cv–00384 (D Ariz., Feb. 13, 2006), ECF Doc. 172–3, p. 49. Arizona courts wo uld give this self-reported and uncorroborated evidence “little . . . mitigating weight.” State v. Sharp , 193 Ariz. 414, 425, 973 P. 2d 1171, 1182 (1999); accord, State v. Gerlaugh , 144 Ariz. 449, 462, 698 P. 2d 694, 707 (1985). Jones’s physical-abuse allegation against Randy is not much more helpful. Granted, his sister seconded his alle

gation. 4 Record 982–987. But other record evidence con

tradicts it. For instance, Jones told Dr. Potts that Randy13 Cite as: 602 U. S. ____ (2024)

Opinion of the Court was “quite stern and a disciplinarian yet certainly not phys

ically abusive .” Id ., at 1067–1068 (emphasis added). On another occasion well before this litigation, Jones said that “[a]s far as I’m concerned,” Randy “is my real dad[;] he’s the only one that has treated me good. He has never hit me or anything .” Id ., at 1020 (emphasis added). Given Jones’s “obvious motive to fabricate, ” Arizona courts would view this abuse allegation with some “skepticism.” State v. Medrano , 185 Ariz. 192, 194, 914 P. 2d 225, 227 (1996); see also Gerlaugh , 144 Ariz., at 462, 698 P. 2d, at 707; State v. Carriger , 143 Ariz. 142, 153, 692 P. 2d 991, 1002 (1984). And even crediting the allegation, it suffers from the same weakness that led the Arizona courts to discount Jones’s other abuse allegations: it is not causally connected to the murders.

4 Finally, Jones points to evidence of substance abuse, namely, that his grandfather introduced him to drugs and alcohol when he was “only nine years old.” Brief for Re

spondent 44. But Jones’s history of substantive abuse was “well-documented” at the time of sentencing. Jones , 185 Ariz., at 491, 917 P. 2d, at 220. The Arizona Supreme Court, for instance, recounted that “by the time [Jones] was 17 years old, he had used many types of drugs and was an alcoholic.” Ibid. ; see also 4 Record 1086–1088 (presentenc

ing report noting that Jones began consuming alcohol and using drugs at 13). And that court gave this fact “some mit

igating weight.” Jones , 185 Ariz., at 491, 917 P. 2d, at 220. There is no reasonable chance that those courts would reach a different result on a second look at essentially the same evidence.

B The weakness of Jones’s mitigating evidence contrasts14 THORNELL v. JONES

Opinion of the Court sharply with the strength of the aggravating circum

stances. These circumstances—multiple homicides, cru

elty, pecuniary motivation, and murder of a child—are given great weight in Arizona. See State v. Garza , 216 Ariz. 56, 72, 163 P. 3d 1006, 1022 (2007) (multiple-homicides ag

gravator gets “ ‘extraordinary weight’ ”); Poyson , 250 Ariz., at 57, 475 P. 3d, at 302 (the cruelty and pecuniary-motiva

tion aggravators are “particularly weighty”); State v. New

ell , 212 Ariz. 389, 406, 132 P. 3d 833, 850 (2006) (young age of the victim is a “compelling aggravating circumstanc[e]” in favor of the death penalty). Indeed, in a host of cases, the Arizona Supreme Court has held that one or more of these aggravating circumstances outweighed mitigation evidence—even evidence that was “not insubstantial.” State v. Hampton , 213 Ariz. 167, 185,140 P. 3d 950, 968 (2006) (concluding that the multiplehomicides aggravator outweighed evidence of a “horren

dous childhood”); see also Poyson , 250 Ariz., at 57–58, 475 P. 3d, at 302–303 (listing several cases in which the multi

ple-homicides aggravator alone outweighed all mitigating circumstances); State v. McKinney , 245 Ariz. 225, 227, 426 P. 3d 1204, 1206 (2018) (cruelty and pecuniary-motivation aggravators outweighed evidence that a defendant had “en

dured a horrific childhood” and suffered from mental ill

ness). Conversely, Jones and his amici identify no cases in which the Arizona Supreme Court has vacated the judg

ment of death in a case involving multiple murders—let alone a case involving all of the aggravating circumstances present here. The absence of such a case strongly suggests that Jones has no reasonable probability of escaping the death penalty.

IV To justify its contrary conclusion, the Ninth Circuit pointed to “the Strickland prejudice analysis conducted by the Supreme Court” in “similar cases.” 52 F. 4th, at 1131.15 Cite as: 602 U. S. ____ (2024)

Opinion of the Court In these cases, the Ninth Circuit stated, we found prejudice when counsel failed to present “classic mitigating evi

dence,” even though the defendants had committed “brutal crimes.” Id ., at 1133. A review of the precedents cited by the Ninth Circuit shows that they are very differe nt from the case now before us. In each of the ineffective-assistance-of-counsel cases on which the Ninth Circuit relied, this Court found that de

fense counsel introduced little, if any, mitigating evidence at the original sentencing. See Porter v. McCollum , 558 U. S. 30, 41 (2009) ( per curiam ); Williams v. Taylor , 529 U. S. 362, 395–398 (2000); Rompilla v. Beard , 545 U. S. 374, 378, 393 (2005); Wiggins v. Smith , 539 U. S. 510, 515, 534– 535 (2003). Jones, by contrast, started with much more mit

igation. And in most of the other cases, the sentencer found only a few aggravating circumstances. See Porter , 558 U. S., at 42 (three aggravators, two of which the sentencing judge thought “were insufficient to warrant death”); Wil

liams , 529 U. S., at 370, 398 (one aggravator); Wiggins , 539 U. S., at 537 (one aggravator). That is a far cry from the weighty aggravating circumstances present here. Poyson

, 250 Ariz., at 57, 475 P. 3d, at 302.

* * * When a capital defendant claims that he was prejudiced at sentencing because counsel failed to present available mitigating evidence, a court must decide whether it is rea

sonably likely that the additional evidence would have avoided a death sentence. This analysis requires an evalu

ation of the strength of all the evidence and a comparison of the weight of aggravating and mitigating factors. The Ninth Circuit did not heed that instruction; rather, it down

played the serious aggravating factors present here and overstated the strength of miti gating evidence that differed very little from the evidence presented at sentencing. Had the Ninth Circuit engaged in the analysis required by16 THORNELL v. JONES

Opinion of the Court

Strickland , it would have had no choice but to affirm the decision of the District Cou rt denying habeas relief. We therefore reverse the judgment of the Court of Appeals and remand the case for further proceedings consistent with this opinion.

It is so ordered._________________

_________________ 1 Cite as: 602 U. S. ____ (2024)

S OTOMAYOR , J., dissenting 

## SUPREME COURT OF THE UNITED STATES

No. 22–982

RYAN THORNELL, DIRECTOR, ARIZONA DEPARTMENT OF CORRECTIONS, PETITIONER v . DANNY LEE JONES

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT
[May 30, 2024]

J USTICE S OTOMAYOR , with whom J USTICE K AGAN joins, dissenting. I agree with the Court that “the Ninth Circuit all but ig

nored the strong aggravating circumstances in this case.” Ante , at 1. That was error. As part of the prejudice inquiry for ineffective-assistance-of-co unsel claims, courts must “consider all the evidence—the good and the bad,” Wong v. Belmontes , 558 U. S. 15, 26 (2009) ( per curiam ), and must “reweigh the evidence in aggravation against the totality of available mitigating evidence,” Wiggins v. Smith , 539 U. S. 510, 534 (2003). The majority unnecessarily goes further and engages in the reweighing itself. See ante, at 8–14. The record in this case is complex, contested, and thousands of pages long. In light of this “extensive record” and “intricate procedural history, . . . this is not an appropriate case to reach and set

tle [a] fact-sensitive issue.” CRST Van Expedited, Inc. v. EEOC , 578 U. S. 419, 435 (2016). That is particularly true when, as here, the majority in the first instance parses a complex record containing co ntested medical diagnoses and disputed allegations of abuse and trauma. “It is not the Court’s usual pr actice to adjudicate either legal or predicate factual questions in the first instance.”2 THORNELL v. JONES

S OTOMAYOR , J., dissenting

Ibid. ; see also Cutter v. Wilkinson , 544 U. S. 709, 718, n. 7 (2005) (“[W]e are a court of review, not first view”). Because I would vacate the judgment below and remand for the Ninth Circuit to consider the full record in the first in

stance, I respectfully dissent._________________

_________________ 1 Cite as: 602 U. S. ____ (2024)

J ACKSON , J., dissenting 

## SUPREME COURT OF THE UNITED STATES

No. 22–982

RYAN THORNELL, DIRECTOR, ARIZONA DEPARTMENT OF CORRECTIONS, PETITIONER v . DANNY LEE JONES

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT
[May 30, 2024]

J USTICE J ACKSON , dissenting. In its search for legal error in this capital habeas case, the Court makes many mistakes of its own, including mis

reading the Ninth Circuit’s opinion.* I write separately to emphasize a particular misstep: the Court’s conclusion that “the Ninth Circuit all but ignored the strong aggravating circumstances in this case.” Ante, at 1. In my view, the Ninth Circuit’s analysis satisfied its obligations under Strickland v. Washington , 466 U. S. 668 (1984).Per our longstanding test for evaluating an ineffectiveassistance-of-counsel claim in a capital case, a court “must consider the totality of the evidence” and ask “whether there is a reasonable probability that, absent the [trial counsel’s] errors, the sentence r . . . would have concluded that the balance of aggravating and mitigating circum

stances did not warrant death.” Id ., at 695. That is pre

cisely what the Ninth Circuit did here. The panel not only evaluated the mitigating evidence that Jones’s trial counsel

——————

*Compare, e.g. , ante , at 7–8 (accusing the panel of “appl[ying] a strange Circuit rule that prohibits a court in a Strickland case from as

sessing the relative strength of expert witness testimony”), with Jones v. Ryan , 52 F. 4th 1104, 1129 (CA9 2022) (“This is not to say, of course, that a district court is prohibited from making credibility determinations”).2 THORNELL v. JONES

J ACKSON , J., dissenting failed to unearth, it also specifically considered all of the aggravating factors. See Jones v. Ryan , 52 F. 4th 1104, 1131 (CA9 2022). To assess prejudice, it then reasoned ex

tensively—by analogy—considering precedent where both the Circuit and this Court had granted habeas relief even in the presence of similar aggravators. See id ., at 1131– 1133. To be sure, the Ninth Circuit’s discussion of the aggravat

ing factors was concise. But there is no benchmark length for any such discussion. Indeed, this Court has granted ha

beas relief after similarly succi nct evaluations of aggravat

ing factors. See, e

. g ., Porter v. McCollum , 558 U. S. 30, 41– 42 (2009) ( per curiam ) (discussing aggrav ators in one para

graph); Rompilla v. Beard , 545 U. S. 374, 390–393 (2005) (no discussion of aggravators); Wiggins v. Smith , 539 U. S. 510, 534–538 (2003) (same). We can hardly fault the Ninth Circuit for using the same approach that this Court itself has previously used. Thus, to me, the Court’s claim that the Ninth Circuit “all but ignored” the aggravators, ante, at 1, rings hollow. And the majority’s real critique does not appear to relate to the Ninth Circuit’s methodology. Rather, it merely takes issue with the weight that the Ninth Circuit assigned to each of the relevant facts. I agree with J USTICE S OTOMAYOR that we are not the right tribunal to parse the extensive factual record in this case in the first instance. That is doubly true where the Ninth Circuit committed no legal error in review

ing that record to begin with. I respectfully dissent.