This article examines the implications of the body of research that asserts that psychopaths have neurobiological irregularities that are manifested by learning and fear-processing deficits as well as neurotransmitter abnormalities. While this research suggests that psychopaths may have many neurobiological irregularities, the present article focuses on abnormalities related to the amygdala and orbitofrontal cortex of the brain, in addition to those related to neurotransmitters. It is argued that these irregularities influence the conduct of psychopaths and help to explain their propensity to engage in antisocial behavior. Further, it is argued that these factors should mitigate the degree of criminal responsibility that is attributed to the actions of psychopathic offenders. References (Published Abstract)