existence of that injury to serve as a humanizing and therefore mitigating factor during sentencing. See, e.g., Skipper v. South Carolina, 476 U.S. 1, 4-5, 106 S.Ct. 1669, 90 L.Ed.2d 1 (1986) (“Although it is true that [the evidence] would not relate specifically to petitioner’s culpability for the crime he committed, there is no question but that such [evidence] would be mitigating in the sense that [it] might serve as a basis for a sentence less than death.” (citations and quotation marks omitted)). The very existence of organic neurological problems may serve as mitigating evidence at sentencing by eliciting sympathy or, at the very least, some degree of understanding from the sentencer. See Douglas, 316 F.3d at 1090; see also Hendricks v. Calderon, 70 F.3d 1032, 1043 (9th Cir.1995) (<HOLDING>). Though the dissent mocks the fact that
holding that counsels failure to investigate the defendants personal and psychiatric history constituted ineffective assistance during the penalty phase but not during the guilt phase holding that trial court had discretion to admit relevant photographs in penalty phase holding that mental health evidence could be mitigating at the penalty phase even though it is insufficient to establish a legal defense to conviction in the guilty phase holding that for habeas relief to be granted based on constitutional error in capital penalty phase error must have had substantial and injurious effect on the jurys verdict in the penalty phase holding that the miscarriage of justice test is not met where the basis for the claim is that an alleged constitutional error prevented additional mitigating evidence from being introduced at a penalty phase hearing