UKGuy, I think one of the most frustrating things in discussing this case are the sheer number of things we don't know.
That said, by 'forensic evidence' on the turtleneck I guess I was thinking that if JBR had worn it at the time of her death, and it had then had to be removed from her dead or dying body, some evidence of that fact would be present, e.g. some traces of the mucous on her face someone mentioned on another thread being transferred at that time to the shirt. I would think that even if PR had said, well, she was crying when we fought over the shirt, there would be some evidence connecting the turtleneck to JBR's dead body, if it had indeed been removed from her body and replaced with the white Gap top.
If I understand BC's EA theory (I'm not sure I do, completely) the 'breath control' device would have been over the turtleneck, if JBR had still been wearing it. In that case, I think there'd be at least some fiber evidence of that, in that along with PR's fibers on the rope there'd be 'turtleneck fibers' of some kind.
Though I respect all posters and their theories, I don't really buy this particular BDI scenario. My objections include (but aren't necessarily limited to) the following:
-the time element. Though we don't know exactly what time the R's arrived home the night of the murder, we do know from several sources that it was unlikely they reached home before 9pm. Even if the children were in bed by 9:30pm and the adults by 10pm (earlier than any scenario suggested so far) we then have to believe that sometime later BR and his 'unknown' friend (was the friend known to be spending the night, btw? or did BR have to sneak downstairs and let the friend in?) convinced JBR to go downstairs quietly with them, fed her some pineapple, fashioned the 'elaborate' garrotte, engaged in sex games, and then 'accidentally' kill JBR, though not until the minimum two hour pineapple digestion process takes place. BR and his 'friend' then write the RN (? have I got that right?) and sneak back to bed; JR and PR stumble upon the corpse later, and frantically stage a crime scene. All of this must take place between 10pm and 5:52am; in fact, even if you assume the parents to be in bed by 10pm, I think you'd have to give them at least a half-hour to be asleep before the children decide to go play sex games with each other. Honestly, it strains the bounds of credibility to believe that so many different people can be sneaking around that house eating pineapple, fashioning EA devices (did they have a book or something? I've known lots of 9-year-olds, but have never known one so jaded with sex that he has to string up his little sister to create a scenario; just sayin'.), writing the 'war and peace' of ransom notes, and wiping down and staging the body, all in what at its most generous estimation is approximately a seven-hour window.
-the ransom note. Even if you get around the time element problem, BlueCrab appears to believe that BR wrote the RN. Now, I know there was a dictionary handy, but again this strains credibility. The ease of writing and the overall articulate nature of the note, the good grammar and (to me the kicker) correct punctuation, and the use of the inverted carat to insert the word 'not' all argue loudly against its having been written by anyone that young. I could buy that a boy could write a note which borrows heavily from movies and television, but I can't buy the idea that a nine-year-old knows how to use periods and commas correctly, knows that an exclamation point signals the end of a sentence and therefore requires that the next word in the sentence begin with a capital letter, or understands the principles of contractions and correctly uses an apostrophe in such words as "Don't."
-the presence of an unknown person in the house that night. If I could believe that someone besides the R's was in the house that night, I could be an IDI! But there's simply no evidence that anyone else was there on that night. The R's calling all their neighbors over the next day may have been intended to confuse and contaminate the crime scene, but BR was sent away; no little friend was called to come keep him company, a logical proceeding if someone else had been there that night and might have left evidence of his presence in the house.
-the complete lack of a specific type of evidence. If this was an actual, bona fide sex crime committed by men of any age, you'd expect a certain substance to be found on, near, or in the body (sorry if that's too graphic.) This would be even more true of pre-adolescent males, would it not? But the only trace of any substance of the type to which I'm referring was found on the blanket belonging to JAR, and was traced to him, if I'm not mistaken.
-the silence of BR himself. Now, I know this one's a bit arguable, but I think if he'd been responsible for the crime, he would have been the most likely to reveal that fact at some point, to someone. Given that he couldn't be prosecuted anyway, wouldn't he at some time in his life have either deliberately or inadvertently revealed the truth?
-the Karr debacle. If the State of Colorado believes it knows the truth about the death of JBR, and by its own laws has to protect the minor involved in the crime, why such an expensive and public fiasco of bringing into custody a man that basic police work would have cleared long before the DNA test?
Sorry this is so long. There are other, minor points against BDI in general and BC's theory, in my opinion, but these are the major ones.