no rana. just because there isn't a law for every conceivable circumstance doesn't mean that one would get custody by being a rapist. Character, possible threats to the child, child endangerment, good emotional upbringing, etc are all factors that WOULD be considered for the interests of the child that this rapist would almost certainly fail.
Yes, Grind, it happens, that is why this young woman is an activist trying to get the laws changed. Ms. Prewitt is a lawyer and here is an excellent paper she wrote on the issue. It s an eye opener, well for one it is an eye opener, for others, they will continue to deny the facts.
http://georgetownlawjournal.org/files/pdf/98-3/Prewitt.PDF