Criminal Responsibility & the Neuroscience of Intent

The brain is a complex and fragile organ which can be damaged by traumatic injury, tumors, neurodevelopmental disorders, neurodegenerative disorders, vascular lesions and many other causes. Episodic or chronic substance abuse can alter both the structure and functioning of the brain. These various forms of injury can affect regions of the brain associated with higher intellectual functioning, memory and emotion, and are particularly relevant to behavioral change. Data has shown that behavioral changes are the result of a complex interplay between the nature and severity of the brain injury and a host of other social and psychological factors. In addition, some of these illnesses or injuries may have genetic contributions, and recent discoveries in behavioral genetics may have implications regarding the heritability of neurologic and psychiatric conditions. However, these relationships are neither linear nor simple.

Despite this uncertainty, brain images and genetic tests are currently being introduced in legal proceedings for the purpose of characterizing these conditions or injuries. Evidence is typically introduced to support the proposition that a criminal defendant should be excused from criminal responsibility because an underlying brain defect caused the individual to commit a criminal act. It has also been introduced as mitigating evidence in the sentencing phase of trials for a capital crimes. The proponents of using neuroscience evidence in the courtroom argue that the introduction of these brain scans will empower judges and juries to draw more accurate conclusions about whether a defendant is responsible for his or her actions. Opponents fear that these images have not yet been reliably linked to the explanation or prediction of behavior, and that their colorful presentation and scientific appearance will be overvalued and misunderstood by judges and juries.

The project on criminal responsibility will focus on the role of neuroimaging, neuropsychology and behavioral genetics in the courtroom, and their correlation with criminal responsibility. The overarching goal of the project is to develop a set of scientific guidelines that would delineate which uses of neuroscience in the courtroom have current scientific support, and which uses are as yet speculative. The first project will be a review of the current uses of neuroimaging in criminal trials, and in particular, in cases where the defendant alleges that the crime was committed with an impaired mental state. The second project will be an examination of the use of behavioral genetics in the courtroom. Subsequent research projects will involve determining how courts in the United States view and treat neuroscientific evidence in a criminal context and how the public perceives neuroscientific evidence presented to diminish responsibility. Once the legal paradigms and evidentiary standards are clear, we intend to generate, publish and disseminate clinical evaluation guidelines tailored to the symptoms under investigation.

The long range goal of this research program is to tailor useful clinical evaluation guidelines to the existing standards for criminal responsibility. It is our hope that widespread acceptance of rational and valid neuroscientific evaluations that are tailored to legal standards will enhance the validity of sound exculpatory defenses while decreasing the inappropriate use of science to diminish responsibility.