This book is offered to the public in the belief that the three cases herein described are typical of a large proportion of criminal cases and that the analysis and discussion attempted will help to make clear important points which are often misunderstood, points relative to the criminal and to the imbecile.
These cases are unique in that they were the first court cases in which the Binet-Simon tests were admitted in evidence, the mental status of these persons under indictment being largely determined by this method.
It happens, also, that these cases well illustrate three phases of the workings of defective minds. Jean Gianini shows the criminal imbecile of high grade and of loquacious type working by himself. Roland Pennington, equally high grade but of a quiet, phlegmatic temperament, shows how a defective mind works under suggestion. Finally, Tronson shows the crude brutality of a somewhat lower grade defective.