Tuesday, December 15, 2009
The defense argued that Dugan suffers from psychopathy, a psychiatric disorder typified by antisocial behavior, impulsivity, and lack of remorse, which made it difficult for him to control his behavior. As a result, the defense argued, Dugan is less culpable for his criminal behavior, and his disorder should be considered a mitigating factor. Kiehl testified that based on functional magnetic resonance imaging (fMRI) tests and a diagnostic checklist, Dugan showed abnormal brain functioning and responses similar to other psychopaths Kiehl has tested. Although data from other brain imaging techniques, such as PET and SPECT, have been used in court previously, Kiehl’s testimony may be the first instance in which fMRI data was admitted in a criminal case.