Scholars following the use of cognitive neuroscience in law have correctly surmised that the most prevalent reported use of this evidence has been as mitigating evidence in capital sentencing. Some trial counsel forego introducing such evidence because of its double-edged potential. Thus far, it appears that courts and jurors give minimal mitigating weight to, or are unsure of how much mitigating weight to afford this evidence. But the black box of jury decision-making and the skewed perspective of reviewing only published appellate opinions make the real system-wide impact of this evidence presently unknown.

An empirical study that I have just completed on relevant criminal cases (published between 2004-2009) illustrates a much broader and increasingly more varied use of such evidence. The cases reported today demonstrate both the novel and the protoypical uses of behavioral neurobiological evidence.

Brain Dysfunction, Memory and the Blackout Defense
State v. Allsup, 2011 WL 332734 (Ohio App. 3 Dist. 2011)
This is a terrific case to foreshadow the impeding onslaught of neuroscience-based memory claims. The defendant brought this appeal from the judgment of the Court of Common Pleas finding him guilty of (among other things) failure to comply with an order or signal of a police officer and felonious assault on a peace officer with a deadly weapon. On appeal, the Defendant claims that the trial court erred in excluding relevant expert testimony regarding his head injuries and subsequent blackouts. At trial, the defendant entered a plea of not guilty by reason of insanity, (“NGRI”), to all the charges listed in the indictment. In a pre-trial motion, the Defendant entered a motion for neuropsychological testing. He argued that his NGRI defense was based upon a mental defect or injury resulting from a head injury he suffered when a tree limb fell on him weeks prior to the incident. As a result, he suffered severe lapses in memory such that he had no recollection of the police chase and surrounding events. The trial court ruled to exclude the evidence of the Defendant’s head injury on the basis that it improperly attempted to establish a diminished capacity defense, and simply served to mislead the jury. A mere failure to remember an event does not, the court explained, excuse its occurrence unless the failure to remember signifies involuntary or unconscious conduct. The proffered defense testimony failed to establish that the Defendant was unconscious or acted involuntarily when he was involved in the police chase. That the Defendant could not remember the incident, standing alone, was insufficient to demonstrate that he lacked the ability to form a specific intent to adequately establish a “blackout defense.” The court found no error in the trial court’s decision to exclude the proffered evidence on the basis that the testimony was both irrelevant and could potentially be misleading to the jury.

Brain Dysfunction and Cruel and Unusual Punishment
People v. Pela, 2011 WL 340536 (Cal.App. 3 Dist. 2011)
In this case the Defendant unsuccessfully used his cognitive disorder, in conjunction with his claim of inadequate medial treatment available to prisoners in California prisons, to argue it would be cruel and unusual punishment to incarcerate him for the 46 years and 8 months sentence he received for his convicted of 11 counts of robbery. At trial the defendant argued that his “mood disorder” leads to “cycles of depression and manic behavior” and that his organic bipolar disorder made him a robber out of an “honest, upstanding churchgoer.” His grandmother’s death “triggered a ‘kindling’ event in the brain” that made him susceptible to “a debilitating mood disorder” and that “[w]ithout help or insight into his mood disorder, he became engulfed in cycles of depression and manic behavior that led to withdrawal and hopelessness on the one hand, and impulsive and reckless behavior on the other.” With respect to the sentence length, the trial court found that “any mental health problem defendant had was relatively minor” and therefore the sentence length was not excessive. As to the 8th Amendment claim, the Defendant has a remedy – to insist that the prison authorities provide him with adequate medical care as needed, including adequate mental health care.

Brain Dysfunction and Capital Mitigation
Ray v. State, 2011 WL 339587 (Ala. Crim. App. 2011)
Another failed attempt at claiming IAC for failing to introduce mitigating evidence during capital sentencing. The defendant was convicted of murder during the course of a rape and a robbery. The jury (by a vote of 11-1) recommended he be sentenced to death, which the circuit court followed. The conviction and sentence were affirmed on direct appeal. Here, the Defendant unsuccessfully appeals the denial of a post-conviction petition he filed attacking his capital-murder conviction and death sentence. Among other arguments, he claims to have received ineffective assistance of counsel during the penalty phase of his capital-murder trial because his trial counsel failed to introduce expert mental health testimony. At the post-conviction evidentiary hearing, the Defendant introduced expert testimony that the Defendant had an “anomalous brain development that causes [him] to suffer severe problems with interpersonal relationships and self control,” and that his IQ is 80, which places him in the level of low mental functioning. To rebut the mental health evidence, the State introduced expert testimony to the contrary, in which the expert opined that there was no need for neuropsychological testing, because the defendant had no history of “head trauma, head injury, [or] neurological disease.” This appellate court found the mitigating evidence weak, at best, and that there was no prejudice to the Defendant in not having had the mental health evidence introduced at trial.