With the availability of new functional and structural neuroimaging techniques such as single-photon emission computed tomography (SPECT), positron emission tomography (PET), magnetic resonance imaging (MRI), and functional MRI, it is now possible to examine regional brain dysfunction with a higher sensitivity and accuracy than was previously possible. This new capacity to view the brain in action has broadened understanding of the neural circuitry that underlies emotional regulation and associated behaviors. Studies of the regulation of emotion derived from neurobiology and neuropsychology show the relevance of prefrontal structures, subcortical structures, and their balance of activity to an understanding of aggressive and/or violent behavior. Functional and structural neuroimaging has shown that decreased prefrontal activity and increased subcortical activity may predispose individuals to antisocial behaviors regardless of factors in the psychosocial environment. Further progress in the study of these behaviors will require a forensically informed, interdisciplinary approach that integrates neuropsychological and psychophysiological methods for the study of the brain, emotional processing, and behavior. To date there has been little or no input from criminology and criminal justice regarding the performance and findings of neurobiological research, largely due to criminology's aversion to biological explanations of criminal behavior. It is imperative that the field embrace an inclusive interdisciplinary model for criminal behavior. 64 references