Findings

• the 41 murderers had significantly lower glucose metabolism in comparison to the control group
• murderers had significantly lower parietal glucose metabolism than controls, especially in the left angular gyrus
• murderers were identical to controls on temporal lobe glucose metabolism
• murderers were found to show significantly higher occipital lobe glucose metabolism than controls
• in comparison to controls, murderers showed an abnormal asymmetry of activity with reduced left and increased right activity in the amygdala and hippocampus
• there were no significant differences for the amount of midbrain and cerebellum activity between murderers and controls
• the groups did not differ on any aspect of behavioural performance on the continuous performance task
• the findings do not establish casual link between brain dysfunction and violence
• Raine made it clear that social, psychological, cultural, and situational factors also play important roles in predisposing to violence
• findings cannot be generalised at the present date from NGRI murder cases to other types of violent offenders
• the data does not demonstrate that murderers pleading NGRI are not responsible for their actions, nor do they demonstrate that PET scans can be used as a diagnostic technique
• Raine stated that the findings of his research cannot be used to demonstrate that violence is determined by biology alone