The idea that the electroencephalogram (EEG) may contribute to our understanding of criminal behavior is relatively old. Individual case reports of EEG abnormalities in violent criminals have been appearing since the early 1940s (Hill & Sargant, 1943), and the association between violent crime and EEG abnormalities with or without clinical epilepsy has been studied ever since.

Most of these studies were based on visual inspection of EEG tracings (rather than on computerized EEG analyses). The subjects were typically prisoners. One of the best studies of this type (Williams, 1969) used 333 prisoners who had committed violent crimes. The subjects were divided into two groups: repeated violent offenders and those who had committed a single violent act. EEG abnormalities occurred in 64% and 24% of the first and second group, respectively. Subjects with mental retardation, clinical epilepsy, or a history of major head injury were removed from both groups. The distribution of EEG abnormalities then changed to 57% and 12% in the first and second group, respectively. These findings suggest that EEG abnormality was related to violent crime in this prisoner sample even after the author accounted for the effects of gross organic brain disease.

The relation between epilepsy, EEG, and aggression has been debated for several decades. Mark and Ervin (1970) reported that patients with temporal lobe epilepsy are prone to aggression during or immediately after their seizure states. However, Rodin (1973) observed epileptic seizures in 150 patients, 42 of whom had psychomotor automatism during a seizure and 15 of whom had it immediately following a seizure.