I've heard several reporters ask about the keys. But they didn't get an answer. At least as far as I heard. I too, wondered about someone (the perp) taking the keys and going to the apartment, but 1) they would have to have known where she lived, and 2) if its a random killer why didn't he take anything? Any money in the wallet??
And if it was a random killer looking for valuables, why was her ring left on her finger? She was found wearing a favorite initialed ring.