Whether the Sixth Amendment requires a court reviewing an ineffective assistance-of-counsel claim to consider the cumulative prejudice stemming from the totality of trial counsel's deficiencies under Strickland v. Washington

After a panel of Ninth Circuit Court of Appeals granted Danny Lee Jones habeas relief finding that his Sixth Amendment right to the effective -assistance -ofcounsel was violated at his 1993 capital sentencing proceeding when his trial lawyer failed to secure a defense mental health expert (Claim 1) and failed to seek neurological and neuropsychological testing before sentencing (Claim 2), this Court reversed. Thornell v. Jones , 602 U.S. 154 (2024). In so doing, this Court held that Jones failed to demonstrate that his trial lawyer’s failures at issue in Claims 1 and 2 prejudiced him within the meaning of Strickland v. Washington , 466 U.S. 668 (1984). However, this Court’s decision in Jones only addressed ineffective -assistance of counsel Claims 1 and 2 and did not address Jones ’s remaining certified penalty phase ineffective -assistance -of-counsel claim, certified Claim 3; nor did Jones address whether Strickland requires a cumulative assessment of prejudice —a question this Court has never answered but which has divided the lower state and federal courts. The Second, Seventh, Ninth, and Tenth Circuits all recognize and apply a cumulative prejudice analysis when considering ineffective -assistance -of-counsel claims. The Fourth and Eighth Circuits do not. Meanwhile, 26 states assess pr ejudice under Strickland cumulatively, while six states do not. In the remaining states, the highest state courts of last resort have yet to address the question. Jones did not address this issue because the Ninth Circuit never reached it. Jones v. Ryan , 52 F.4th 1104, 1137 (9th Cir. 2022) (“Because we have determined that Jones is entitled to relief and resentencing on the basis of Claims 1 and 2, . . . we need not reach the merits of any of Jones’s other claims”), rev’d sub nom. Jones , 602 U.S. 154. On remand from this Court, the Ninth Circuit affirmed the district court judgment “[p]ursuant to the Supreme Court’s opinion” in Jones without further review. Jones v. Ryan , 106 F.4th 1010 (9th Cir. July 10, 2024). This petition presents the following question: Whether the Sixth Amendment requires a court reviewing an ineffective assistance -of-counsel claim to consider the cumulative prejudice stemming from the totality of trial counsel’s deficiencies under Strickland v. Washington , 466 U.S. 668 (1984) .