Evidence of Brain Injury to Challenge Criminal Convictions and Mitigate Criminal Sentences: Update 2021

Recent Cases in Law and Neuroscience, Curated by the Center for Law, Brain & Behavior and the Shen Neurolaw Lab with support from the Dana Foundation

Center for Law, Brain & Behavior
6 min readMar 21, 2022

In a number of state and federal cases in 2021, defendants proffered evidence of brain injury as mitigating evidence at sentencing. Evidence included: expert testimony from neurologists and neuropsychologists, as well as various brain scans such as MRIs and PET scans. Most of these efforts, however, did not result in mitigation, as courts often identified a missing link: the connection between a verified brain injury and the criminal behavior. At the guilt phase, brain injury evidence seems to appear less frequently, but some defendants did proffer guilty phase brain injury evidence to negate mens rea and actus reus.

Brain injuries have been introduced by defendants as evidence in the guilt phase of criminal trials. In a 9th Circuit Court of Appeals case, defendant Cubby Williams contended that the district court erred in excluding expert testimony on his brain injury and its effect on memory. Williams sought to use the expert testimony on poor memory to refute the government’s allegations that Williams intentionally violated tax laws. The Court of Appeal affirmed the trial court’s ruling, however, finding that the brain injury would not have affected Williams’ ability to form the necessary mens rea.

Additionally, in a Florida case, 56-year-old retired Navy officer Albon Diamond was charged with engaging in sexual activity with his minor step-grandson and sentenced to life imprisonment. In his Petition for Writ of Certiorari to the Eleventh Circuit Court of Appeals, Diamond argued that due to his severe stroke, supported by an MRI scan of his brain showing ”devastating physical damage” caused by the stroke, he was physically unable to engage in sexual activity and thus did not have the necessary actus reus required by the statute. Neurologist Dr. Bear provided expert testimony that due to the stroke, Diamond could barely walk, had no use of his left hand, and was very weak, so it would have been “physically impossible” for Diamond to engage in the alleged sexual activity at that time. The state trial court found the testimony credible and noted Diamond’s physical weakness, but believed the State’s testimony that even with the disability, Diamond would still have been able to commit the crimes he was charged with. Diamond.

Brain injuries have been more often used during sentencing appeals. But in the recent cases reviewed here, this evidence was not successful in mitigating sentences.

One male litigant, claimed they had a brain injury, but were found to have “structurally normal” brains.

In contrast, in a Texas case, defendant Henry Davidson suffered post-traumatic brain injuries, including an alleged brain bleed after a car accident, that resulted in lasting damage. Defense counsel presented an oral motion for continuance to have time to find a neurologist to present expert testimony, but the lower court denied the defendant’s motion, and the Court of Appeals affirmed. As such, neither court applied the evidence of brain injury to Davidson’s sentence of life in prison for aggravated sexual assault. Davidson.

Similarly, in a Pennsylvania case, the court relied on expert testimony to conclude that the defendant’s traumatic brain injury resolved before the crime occurred. Thus, the court did not give significant weight to the brain injury in the sentencing appeal.

Likewise, in an Ohio case, the defendant filed multiple motions, and presented expert testimony that he suffered from brain dysfunction and impairment due to prenatal alcohol exposure. The defendant claimed that allowing people with fetal alcohol syndrome disorder to face the death penalty violates the prohibition against cruel and unusual punishment and the equal protection clause, but the court denied the substantive motions on appeal without considering the alleged brain impairment.

Lastly, in a California case, defendant Steven Thomas was convicted of first degree murder and felony-murder, and he was sentenced to life without the possibility of parole. Defense counsel argued that due to his brain damage, supported by a brain MRI showing severe brain damage, Thomas was the not actual killer, did not intend to kill, and could not have been a major participant in the killing. Neuropsychologist Dean Delis and neurologist James Grisolia both examined Thomas and believed his mental faculties made him more of a passive follower than a leader. This brain evidence led the jury to have a reasonable doubt whether Thomas was the actual killer. While the jury determined that Thomas did not personally use the murder weapon, the jury nonetheless convicted Thomas of first degree murder at trial. In the subsequent bifurcated penalty phase trial, the jury sentenced Thomas to life without parole and the appeal court affirmed. Thomas.

There were also multiple attempts to use evidence of brain injury as part of mitigating evidence by arguing that the injury led to reduced cognitive function, and therefore the defendant was less culpable.

In a Florida case, defendant Glen Rogers was found guilty of first-degree murder. At sentencing, he called two experts to present mitigating evidence, psychiatrist Dr. Michael Maher and forensic psychologist Dr. Robert Berland. Both experts testified that Rogers suffered from brain damage and porphyria, a genetic mental disorder. Nonetheless, the court sentenced Rogers to death. The Florida Supreme Court affirmed without significant mention or analysis of Rogers’ brain damage. Rogers.

In a Texas case, defendant Charles Reedy was found guilty of murder. At sentencing, he presented mitigating evidence of brain injury, and an expert psychologist testified that Reedy had decreased processing speed, low IQ, and poor memory as a result of the injury, so Reedy may be unable to form intentional or knowing mental states and would instead be reckless in his conduct. However, the state’s expert forensic psychologist testified that Reedy had sufficient mental capability to carry out intentional or knowing acts, so the jury convicted the defendant of murder, and higher court affirmed the trial court’s conviction. In a New Mexico case, defendant Francisco Gonzales was charged with Felon in Possession of a Firearm and sentenced to the 15-year mandatory minimum due to repeated prior convictions. The court noted that the mitigating factors, including evidence of brain injury and its effect on Gonzales’ memory, thinking, and impulse control, were irrelevant because of the statutory minimum.

Similarly, in a 9th Circuit Court of Appeals case, defendant Leroy McGill appealed after being sentenced to death for premeditated first-degree murder and the Court of Appeals affirmed. McGill’s counsel presented McGill’s PET scan, along with a “comprehensive battery” of tests, showing a brain injury as mitigation evidence to show impaired judgment leading up to the crime. Dr. Joseph Wu, the director of the Brain Imagery Center at UC Irvine, testified that the PET scan was insufficient to link brain injury to cognitive disorders. The lower court considered the effect of the brain injury but ultimately disregarded it because that there was no proven causal relationship between the nature of the McGill’s brain injury and his actions. McGill.

One case where the defendant successfully mitigated his sentence with brain evidence was in a Massachusetts, where 15-year-old Raymond Concepcion was convicted of murder and sentenced to life with possibility of parole. The defendant’s expert witness testified that Concepcion had a traumatic brain injury and documented concerns of cognitive delay of a moderate severity. In contrast, the Commonwealth’s expert psychiatrist, who spent only one hour with the defendant, testified that Concepcion’s cognitive ability was in the average range. The jury convicted Concepcion of first-degree murder. However, the Supreme Court of Massachusetts decreased his conviction from first-degree to second-degree murder due to mental illness in conjunction with external duress, as Concepcion was being threatened by gang members. While the brain injury was not directly considered, the court held that cognitive disabilities arising from the injury, as well as PTSD and depression, made Concepcion very susceptible to external manipulation. Concepcion.

As neuroscience research continues to further our understanding of how brain injuries are related to mental states and behavior, courts may become more open to seriously considering evidence of brain injury for criminal culpability and sentencing. As of now, recent cases suggest that courts are generally unconvinced by the applicability of a defendant’s brain injury to criminal sentencing.

Citations: Davidson v. State, 2021 WL 1438305; Rogers v. State, 2021 WL 4997688; McGill v. Shinn, 16 F.4th 666 (9th Cir. 2021)y; Diamond v. Inch, 2021 WL 3081216; People v. Thomas, 2021 WL 5074493; Commonwealth v. Concepcion, 487 Mass. 77 (2021);

Keywords: Arizona, Florida, California, Ohio, Pennsylvania, Texas, Massachusetts, New Mexico, New York, brain damage, brain injury, brain imaging, brain scan, expert testimony, sexual assault, traumatic brain injury, MRI, PET scan

This post is the 114th post as part of an ongoing Center for Law, Brain & Behavior (CLBB) series tracking the latest developments in law and neuroscience cases. To see previous posts about recent cases, see the full case archive on the CLBB website. To see updates on legal scholarship, see the Neurolaw News, hosted by the MacArthur Foundation Research Network on Law and Neuroscience. This project is made possible through support of the Dana Foundation.