Most of the evidence would be found in/on Barb, would it not? Most likely they've done a rapekit and it must've come back positive for signs of sexual intercourse. The only reason why I'd see the police searching the house for more evidence is if they suspect that there's more physical evidence than what they got. (used condoms, lube, etc. anything that could point to signs of sexual activity taking place.) In all likelihood they have all the evidence they need right now, unless they suspect there's more to it.