If you were a prosecutor, there probably would be a responsibility to disclose this. The defense has no obligation in reverse. No one (on the stand) has a duty to disclose more than the questions require.

These cases are extraordinarily difficult. It's hard to know why someone does something.

What difference does it make if I bash your head open because of your race or sexual orientation? It doesn't matter. Your head is broken open. The reason I did it should be of less concern than my actions.