What do you do with this? Would you convict a man -- any man -- of kidnapping, let alone murder on that evidence. I'm an old prosecutor (who has never defended a crook) and yet that gives me pause.
There are at least 3 scenarios possible:
1. Westerfield breaks in while Mrs. VD is out partying and Mr. VD is [unknown], kidnaps girl, takes her to RV, kills her, then leaves her in RV and goes to bar to socialize with Mrs. VD and friends to establish alibi. Then after bar, he drives to desert and disposes of body. Problems: Where is Mr. VD? Westerfield would have to be REAL cool customer to commit such a murder and go off to bar, not knowing when little girl might be discovered missing.
2. Westerfield goes to bar and socializes with Mrs. VD and learns of forthcoming 'adult party'. Realizing that this means that VD's and their 'guests' will be incommunicado in the garage, Westerfield enters house, takes girl, etc etc. May explain why Mrs VD "can't remember" dancing with Westerfield, while he does. Why didn't parents lock house and turn on burglar alarm if they knew (as they did under this scenario) that they would be "occupied" in the garage? Again would require Westerfield to have the nerves of a cat burglar to pull it off (going into small house with 6 adults in proximity).
3. Westerfield is either at adult party with Mr and Mrs or is called to it after they (or guests or some combination) kill (perhaps accidentally) little girl and Westerfield agrees to dispose of body. This would make Westerfield an accessory after the fact but put him in difficult spot without some corroboration of parents' involvement. This would explain all physical evidence but not make Westerfield guilty of murder. Charge could be designed to turn Westerfield. This also explains the bizarrely aloof behavior of Mr and Mrs.
One thing (one thing?) we don't know (or at least I haven't seen) is much about timing, i.e. what time does Westerfield arrive at state park versus when Mrs. leaves the bar with 4 "friends". None of these scenarios are satisfying to me and there are none I would want to try and make a murder conviction on -- without more.
One thing for sure this case will take the OJ slot for the foreseeable future.