Another case that this reminds me of is the (extremely sad) Whitney Heichel case in Oregon a few months ago. Her car was found parked at a local WalMart, and her cell phone was found tossed in some bushes quite a ways away. Now in that case, the police had evidence that something bad had happened - her car window was smashed out, and then they found some of her belongings in a nearby park. Then they found her body, and a neighbor was arrested and charged with her murder. The whole case moved a lot more quickly than this one, but I remember for a few days there, we (websleuths) were wondering about the silence and apparent lack of activity. OH, and the cops kept saying that they didn't even know if a crime had been committed (when in reality, they did know, and had their eyes on this suspect most of the time. we didn't know it, but they'd been questioning the guy).
I guess, thinking back on that case, I'm wondering if it is at all possible that she could have been abducted and killed, and then the guy left the car at the apt complex and threw the phone out the window. Could it be that the cops have a suspect (not GR) but not enough evidence to arrest someone, and are waiting for the guy to mess up??
I didn't originally think anything but her running away or GR doing something, but just as there are good arguments for each of these scenarios, there are also very good arguments against each of them. Which leaves, what??