Is the criminal mind different from the non-criminal mind? The emerging field of “neurocriminology” is saying “yes.” A look inside the brain of serial killers and other murderers reveals definite abnormal patterns, especially with regard to that structure called the amygdala. Recent research findings will be reviewed and both biological and environmental factors contributing to criminal behavior will be identified. The question will be raised, “What are the implications of neurocriminology for the Criminal Justice System?” Suggestions for future directions in this field will be presented and explored.