Subsequent surveys didn’t bear out this proposition. One Scandinavian study of nearly a thousand epileptics found no excess of criminal activity if there existed no psychiatric disorder. More recent studies of the prevalence of epilepsy in prisons in the United Kingdom, found epileptics to be slightly more represented, but this can only establish that they are more likely to be sent to prison, not that they are more likely to be criminal (besides, these results were not confirmed in similar studies done in Italy and France).
In any case, their criminal offences are not likely to be more violent than those of other prisoners. Thus, any link between dangerousness and epilepsy is probably due to its complications or associations rather than to the attacks themselves and this connection should never be made as a general rule.