"Totally crazy" generally speaking means some flavor of psychotic. His impulses and personality issues would be classified as a mental illness, Axis II in the D

"Totally crazy" generally speaking means some flavor of psychotic. His impulses and personality issues would be classified as a mental illness, Axis II in the DSM, but they would be largely resistent to treatment. Nothing that would be easy to ascribe to him (from a distance) would have damaged his hold on reality. There is still a raging debate as to whether much of the world of personality disorders represents actual disorders, or just extremes in the variance of human behavior and temperament. That is to say, maybe he was rational, aware of the impact of his actions, and yet he wanted to do it because it was egosyntonic. Contrast that with some like Jared Lee Laughner, who is was a classic paranoid schizophrenic. I think that is what most people think of, when they think of "Totally crazy". Someone talking at the air, clanging and chattering word salad; someone broken from reality.