If John Allen Mohammad is "Mad" --mental illness--?

Different states have different standards as to what constitutes mental illness. The McNaughton rule, the model penal code, etc. Some places it is not knowing the difference between right and wrong, some places it is an in ability to control your actions even if you know it is wrong. One found insane in one state may not in another. And the Manson thing was because the death penalty was ruled unconstitutional as it was implemented at the time so his sentence was commuted.