Don't flame me for this but...is anyone else here as creeped out by the (younger, not present-day) BR as I am?
Not that I am implying he was involved (though I won't rule it out) but his demeanor that day, and just the things I've read about his reaction to the death of his little sister (or lack or reaction, a better wording). He just seems like a strange kid to me. Disconnected somehow. I've seen (here) his MySpace page, and it seems he grew up to be a reasonably normal kid, at least from what little can be seen on that site. But he's keeping an awful lot inside. Every parent deals with their kid differently, but parents trying to find out who killed their child in their own home would be asking their other child relentlessly about anything they'd seen/heard that night- anything. I've read varying interviews where the R's say they thought he was sleeping through all the commotion and just left him there, then I've seen where they actually admit he was awake for the 911 call, but decided not to bring that info forward to keep him out of it.
I also don't think I'd stonewall to keep him from being interviewed by the very LE people I was expecting to solve this crime. Those actions are exactly the opposite of what innocent people would do. I can understand not wanting to have a younger child, say 2-5, pressed for information- too traumatic, probably not useful, but BR was 9. And he was into his video games, etc, I am sure he was an intelligent kid at that age, so why not try to find out if he had anything to add, even if he has seen/heard anything said to his sister at the party Christmas Day or on the 23rd. And there have been cases where even a younger child has given valuable information in crime investigations.