Part of me hates to say this, but I suspect that while Tim's testimony will be crucial to convict KC, I also suspect that it will help insure that the jury does not choose the DP. His descriptions of her make her seem so far outside the psychological norm that regardless of mental health evaluations or expert testimony the jury will come to their own conclussions and simply will not execute a young woman that they percieve as mentally ill. You combine KC's complete disasciation from Caylee combined with the obvious insanity that is the family life, and they will take pity, guaranteed.