The ninth-circuit affirmed the district court’s denial of Andrew Lamont Brown’s petition for a writ of habeas corpus under 28 U.S.C. § 2254, rejecting his challenges to his California conviction and death sentence for first-degree murder. The panel applied the deferential standard of review mandated by the Antiterrorism and Effective Death Penalty Act (AEDPA), which requires finding that a state court’s decision was contrary to or involved an unreasonable application of clearly established federal law, or was based on an unreasonable determination of facts. Regarding Brown’s certified claims, the court held that the California Supreme Court reasonably determined trial counsel’s performance at the penalty phase was not deficient under *Strickland v. Washington*. The panel found that counsel conducted a reasonable investigation into Brown’s history of drug and alcohol abuse, mental health conditions, family abuse, poverty, and neighborhood environment, and made strategic choices regarding how to present this mitigation evidence to avoid prejudicing the jury. Additionally, the court held that trial counsel was not ineffective for failing to call specific rebuttal witnesses regarding uncharged acts or for failing to object to the prosecutor’s closing arguments describing Brown as a “sociopath.” The panel further affirmed that the state court did not unreasonably determine Brown was competent to stand trial and reasonably concluded Brown failed to make a prima facie showing of intellectual disability under California statutory standards, noting his IQ scores fell within the borderline range and lacked evidence of significant adaptive deficits. The court also declined to expand the certificate of appealability (COA) to include three uncertified claims: ineffective assistance of counsel during the guilt phase, a *Batson* claim regarding the exclusion of a Black juror, and a Sixth Amendment fair-cross-section claim. The panel concluded that reasonable jurists could not disagree with the district court’s resolution of these issues, as Brown failed to demonstrate a substantial showing of the denial of a constitutional right for any of them. As a practical consequence, the judgment of the district court denying habeas relief is affirmed, and Brown remains subject to his death sentence. No further federal appellate review on the merits of the certified or uncertified claims is available under this opinion.