Can the mentally ill be to blame?

Suppose you discovered that someone has committed a horribly violent crime. And now suppose I tell you one additional fact about the person who performed this act: he or she is mentally ill. In fact, suppose I tell you that the reason he performed this act he is suffering from damage to a particular area of his brain. Would you still conclude that he could be morally responsible for what he had done?

Dennis has recently found out from his doctor that he has a neurological condition that has caused him to behave in certain ways. Were someone else to have this neurological condition then that person would have had to behave in the same ways as Dennis.

Dennis has recently found out from his doctor that he has a neurological condition that has, in the past, caused him to rape women. Were someone else to have this neurological condition then that person would have had to behave in the same ways as Dennis.