Long time lurker here, just thinking outloud.
For those that live in the neighborhood, have the police searched the yards of homes in the neighborhood? Have they figured out if there are any abandoned homes in the Westwood neighborhood adjacent to the trails? If JG was able to hide her quickly and had been on foot around the neighborhood a lot, perhaps he knew of a home that no one was living in.
I know just in my Southern California neighborhood there are 4 or 5 homes vacant from foreclosures. I am wondering if heading back towards his own home, he knew where to hide her in a home thats unlived in.
(FWIW, I grew up in the Rancho Bernardo, graduated from Mt. Carmel in 89, which was then where everyone in Westwood went at that time. Spent lots of times walking those streets as a teenager...now having a teenager daughter myself, I am so sad over this whole crime.)