The thing that would make the most sense to me is that she put the dogs downstairs, left her wallet, glasses and contacts there and went for her run. After 15 minutes, give or take a few, someone she knew stopped and talked to her. He/she used some ruse to get her to go with him/her (I'm sticking with him for the rest of this post.) They may have ended up at his house, or somewhere else that didn't make her too uncomfortable/suspicious. When she sent the SC to DJ, it may have set the person off. He may have hit her out of anger that she'd do that when she was with him, or it could have been a different type of assault on her. Whether he killed her there or just knew he'd have real problems if he just let her go, he took her in his vehicle to a place more isolated (it would most likely be dark by then) and either dumped her body or murdered her there and left her. Of course, if it was up to me, he would have taken her phone, gave her drugs to knock her out and put her on a plane to Hawaii or something.