When you talk about a father raped his own child, i see it not as a form of paedophilia but as a form of psychological disorder.
It is practically a taboo where I'm from for siblings to have an affair talk more of a father raping his own child. It is the height of insanity and psychological disorder.
Personally i am biased towards such kind of fathers, if i were to be a judge in this case i would sentence such a father to death by lethal injection because he doesn't qualify to be a father talkmore of calling him one.
However, no matter the reason, rape is a crime punishable by the law and raping one's child is a grievous offence that should be punishable by death because if the law allows such type of father to go to jail, it's like giving him some time off for vacation and he would continue still whenever he gets out of prison and he would be much more lethal.