Well, it could be argued then, that Harris' parents didn't recognize what were probably telltale signs either. And let's not overlook the fact that Harris was in high school whereas CR was 8. It's apples and oranges IMO.
Is it nature or nurture? This question can be asked of any siblings raised in the same household and under the same conditions the world over. CR doesn't have any siblings raised under the same circumstances as he was. So, I suppose we'll never know how his environment may have shaped him. I have 2 brothers and none of us remember anything exactly the same way. Though none of us have ever killed anyone....
Someone earlier said that, in addition to the published facts of these cases, we bring our own life experiences when we weigh in. I do believe that is true. In my case, I can tell you that my son was 2 and my daughter 5 when I left their father. I won't go into the details as to why I left here, but suffice it to say, there were many, many valid reasons. Anyhoo, my wonderful husband and children's stepfather, who long ago adopted my children legally, has pretty much been the only father they remember. Their own father abandoned them long ago. Neither of them show any signs of psychological discord because they know it's not their fault. By the same token, my niece and nephew have been abandoned by their mother - as teenagers - and show no signs, whatsoever, of serious issues. In both cases, the remaining parents have had serious discussions with the kids to address any possible issues. They have been assured it was not because of them or anything they did. That is not to say that it will not affect them in later years.
My point is, I doubt very much that CR felt "abandoned" by his mother from the age of 2. He really never knew anything but being with VR. I guess I'm at a loss to understand how anyone can possibly believe this is the reason to believe he is guilty of what he has been accused.