Book excerpt: His first murder was an accident. A mistake derived from anger. But the others were so well planned that even the authorities at Scotland yard could not find any evidence to convict him. "I'm sorry you feel that way, doctor. Please accept my apologies....but may I reiterate that we are trained in our discipline as much as you are trained in yours. You see, we're forced to see the world differently from everybody else. In any event, we evaluate and calculate in very much the same way an accountant does. The only difference is that, if he makes an error in his calculation, without due justification, he still considers it a mistake, and we call it fraud."