That, too--but the news stories said that Danielle's blood was found on Westerfield's clothing. Of course, they may well have found his seminal fluid on his own clothing, but that'd be explainable by his lawyer. Finding his blood, tissue, hair or seminal fluid (or fiber evidence) in or on Danielle would seal the case.
And if he did do this, I hope that is the gruesome find, for obvious reasons. Poor little girl.....I have two daughters, I can't imagine them being used like this, then killed, and burned (although I've been reading she might not have been....)