I used to be a full on "PR did it!" supporter, but when you think long and hard about it, it doesn't really add up. If it's an accident, you call the police. If PR or JR is the intentional culprit, there's just no compelling rationale for why they cover for the other. Again, you call the police. The only way they work together crafting a ransom note and staging the elaborate kidnapping is if the risk (being caught covering up a murder) is worth the reward. What could that valuable reward be, except for the protection of their other child. A BDI theory is the only one that really makes sense. He kills JBR and the parents realize that his life is now ruined. This one act has taken both their daughter AND their son away from them. Panic sets in and suddenly the idea of being able to save their child from prosecution doesn't seem so crazy. If there's an outside chance that the charade will work, the R's decide to risk it so that they won't lose their son and he can have a shot at a 'normal' life. Suddenly all the evidence makes sense. It is just a smokescreen. If the R's did do it, this is really the only logical explanation for the whole entire ruse.