The Afghan Christian could get off on an insanity defense:

“We think he could be mad. He is not a normal person. He doesn’t talk like a normal person,” The AP quoted prosecutor Sarinwal Zamari as saying.
Moayuddin Baluch, a religious adviser to President Hamid Karzai, said Rahman would undergo a psychological examination, according to the AP.
“Doctors must examine him,” the AP quoted Baluch as saying. “If he is mentally unfit, definitely Islam has no claim to punish him. He must be forgiven. The case must be dropped.”