At first — long before indeed — he had been much occupied with one question; why almost all crimes are so badly concealed and so easily detected, and why almost all criminals leave such obvious traces? He had come gradually to many different and curious conclusions, and in his opinion the chief reason lay not so much in the material impossibility of concealing the crime, as in the criminal himself. Almost every criminal is subject to a failure of will and reasoning power by a childish and phenomenal heedlessness, at the very instant when prudence and caution are most essential. It was his conviction that this eclipse of reason and failure of will power attacked a man like a disease, developed gradually and reached its highest point just before the perpetration of the crime, continued with equal violence at the moment of the crime and for longer