I have seen other suggestions as to my first thought at the beginning of this case as an accidental overdose. I definitely think the friend was involved, and I think it's very possible that an accidental OD occured and the friend panicked (maybe thinking that he would be blamed for her death). Thinking about this, maybe the second time the cops were called WAS him dragging the body around, and when he heard them he froze, not answering the door and just hoping they would leave.....then after he made sure they were gone he took her out of the house. He then may have decided that after driving possibly a couple of hours away to return at a gas station for an alibi....I mean if you think about it, that makes sense. I don't understand why search parties aren't searching different woods in different towns???
Also as far as the friend saying all past tense stuff, I believe that everyone believes she is not alive. I don't know how long someone has to be missing for them to be declared legally dead, but I follow crime stories all the time and in MOST cases if they are missing for more than a few days in never turns out good unfortunately.