The Limitations and Potential of Neuroimaging in the Criminal Law

Neuroimaging showing brain abnormalities is increasingly being introduced in criminal court proceedings to argue that a defendant could not control his behavior and should not be held responsible for it. But imaging has questionable probative value because it does not directly capture brain function or a defendant’s mental states at the time of a criminal act. Advanced techniques could transform imaging from a coarse-grained measure of correlations between brain states and behavior to a fine-grained measure of causal connections between them. Even if this occurs, bias and other attitudes may unduly influence jurors’ interpretation of the data. Moreover, judges’ decisions about whether neuroimaging data is legally relevant and admissible are normative decisions based on more than empirical evidence. Advanced neuroimaging will better inform assessments of criminal responsibility but will not supplant or explain away the psychological and normative foundation of the criminal law.