Does brain damage mitigate criminal responsibility or punishment ? Should it count as “good” evidence about a defendant’s reasons for acting that should be balanced against “bad” reasons for his criminal conduct?

In the case of Schriro v. Landrigan, the U.S. Supreme Court dealt with an analogous question about whether a genetic predisposition to violence is mitigating evidence. The other issue in the case, whether a defendant could voluntarily waive his right to have mitigating evidence introduced on his behalf (which Landrigan had), resolved the case. Although the court didn’t reach the question of genetic predisposition, in dicta, it suggests that such evidence was unlikely to have a positive effect on the outcome of the case.

Which way does predisposition evidence cut? Defense counsel have introduced this evidence for mitigation, and the two cases illustrate that trend (a judge calling brain damage “good” evidence in favor of mitigation, and a defendant claiming IAC for failing to investigate his brain damage). But is this evidence actually mitigating? Prosecutors have also recognized its aggravating potential and have introduced it to support predictions of future dangerousness.

What do you think? Does evidence of brain damage make a defendant less responsible or culpable for his criminal conduct?

Jury Instructions, Brain Damage as “good” factors to outweigh “bad” ones, Death Penalty
People v. Nelson, 246 P.3d 301 (Cal. 2011)
A jury convicted defendant of first-degree murder, robbery, and attempted carjacking. Defendant was sentenced to death. On this automatic appeal, the California Supreme Court affirmed the judgment. Of interest is one of the claims that the defendant raises, challenging the voir dire colloquy between the judge and potential jurors regarding death penalty deliberations as de facto instructions. During voir dire the court examined the willingness of potential jurors to impose the death penalty if the aggravating circumstances were so substantial in comparison with the mitigating circumstances that they concluded death was warranted. However, in querying individual jurors, the court used a shorthand expression: “the bad outweighs the good.” For example, the court asked: “If the bad outweighs the good, can you see yourself actually voting for death? The Defense never objected to the shorthand usage, or asked for further elaboration on the point during jury selection. Defendant now contends these colloquies amounted to “de facto instructions” that were prejudicially defective in two respects, one being that the word “good” misleadingly suggested that only positive behavior on the part of the defendant might be considered as a mitigating circumstance. However, the court clarified that “good” was not limited to “good deeds,” but rather included “background” factors, such as a tough childhood” or “brain damage,” that might “explain” the defendant’s conduct and help the jury “decide what the appropriate penalty is.” On appeal the court held that the jury was properly instructed, the court explained its shorthand usage, and there is no evidence that the jury was misled.

IAC, Failure to Investigate, Brain Damage, Equivocal Evidence
Rose v. McNeil, 2011 WL 744967 (11th Cir. 2011)
Petitioner was convicted and sentenced to death for a brutal murder for which there were multiple witnesses. He now appeals his denial of his petition for a writ of habeas corpus. The sole issue presented on appeal is whether Petitioner’s trial counsel was ineffective in the investigation and presentation of mitigation evidence at the penalty phase. During post-conviction proceedings Petitioner introduced multiple experts regarding his sub-average intelligence and neuropsychological test results “consistent with a diagnosis of brain damage,” of minimal nature, “most likely in the right temporal lobe area,” and that he had some degree of “organic brain syndrome” and “chronic alcohol and drug abuse.” The expert testimony was equivocal, where some experts could not “make a definitive diagnosis of organic brain damage,” and others believed at most that he suffered “mild organic brain symptom.” After review and oral argument, the court affirmed, holding that all of the evidence in mitigation, both presented at the penalty phase and post-conviction proceedings, made it unlikely that Petitioner would have received a different sentence had his trial counsel investigated and presented the evidence at issue here. Finding no prejudice, the court did not reach the issue of whether the trial counsel’s performance was deficient.