I've heard and read many different (professional) opinions on just what psychopathology is, some of which hold that a physically identifiable cause of aberrant behavior, such as a brain tumor, must be present to qualify. But I believe capability and motivation are adequate indicators of whether someone can be considered psychologically normal or not.
Timothy McVeigh, for example, was motivated by the BATF's and FBI/HRT's actions at Waco to spend months constructing a massive bomb and detonating it without regard for innocent casualties. While his motivation is understandable, the capability of carrying out such an elaborate act of vengeance with utter disregard for innocent victims is sufficiently abnormal to qualify as psychopathology. In other words, anyone who is capable of doing something that bizarre is a menace to society by virtue of his psychological condition. Is there need for a more technical definition of what insanity is?
Is anyone here willing to say this Holmes fellow isn't crazy? Why should knowing the cause of his pathology be necessary for it to qualify as legal insanity?