A groundbreaking study published by the journal Science shows that judges are likely to be influenced by the results of brain scans that are introduced into evidence.
The brain scan evidence was introduced as part of a hypothetical case that was shown to 181 state court judges. As reported in The New York Times, the hypothetical case involved a man who beat a restaurant manager with the butt of a gun.
In the study, three researchers at the University of Utah tracked down 181 state judges from 19 states who agreed to read a fictional case file and assign a sentence to an offender, “Jonathan Donahue,” convicted of beating a restaurant manager senseless with the butt of a gun. All of the judges learned in their files that Mr. Donahue had been identified as a psychopath based on a standard interview — that is, he had a history of aggressive acts without showing empathy.
The case files distributed to the judges were identical, except that half included testimony from a scientist described as “a neurobiologist and renowned expert on the causes of psychopathy,” who said that the defendant had inherited a gene linked to violent, aggressive behavior. This testimony described how the gene variant altered the development of brain areas that generate and manage emotion.
The neurobiological evidence tended to impact the judge’s sentences in two, contradictory ways. Evidence that the defendant was psychopathic increased his sentence, but evidence that the defendant inherited a gene linked to violent behavior reduced the sentence imposed by the judges.
This study has far reaching and potentially troubling implications, especially for juveniles who are charged with serious, violent offenses. The study makes clear that judges are influenced by neurobiological evidence. On the one hand, that means that prosecutors and judges may rely too heavily on scientific evidence to conclude that a juvenile poses a long-term threat to society. That is what happened when the judges were confronted with scientific evidence that the defendant in the hypothetical was a psychopath. On the other hand, brain scans provide hope that juveniles and others accused of crimes will be treated in a way that takes their individual circumstances, history, and predispositions into account much more than they are today. This is what led judges to show greater leniency based on the testimony of a neurobiological expert.
As a juvenile defense lawyer in Los Angeles, one of my first reactions to reading this study related to resources. Specifically, how on earth is the juvenile justice system going to find the money and other resources to introduce brain scan evidence in juvenile cases? At the moment, brain scan evidence has been introduced in very few cases, most notably in death penalty cases, and usually during the appeal of those cases. Because the brains of juveniles are still changing, neurobiological evidence is potentially more important in juvenile cases than in cases involving adults. This is especially true where juveniles are charged with serious violent crimes.
The article published in Science may usher in the beginning of a new era in the use of brain scans in criminal cases. That may be the future. If it is, the juvenile justice system will need to make enormous changes to make that future a reality.