Penny ran away, but did the cops know that? From the sound of what Rob's saying, he was completely blown off. Sounds like the cops did absolutely nothing, not that they asked around, looked around, and found no evidence. While Penny's case likely demands less investigation than Cindi's, but Rob is also correct in the general case, that there are some folks the police will put more effort into helping than others.
The notes of this paradoxalist do not end here, however. He could not refrain from going on with them, but it seems to us that we may stop here. - Fyodor Dostoevsky, Notes from Underground (trans. C. Garnett)