I'm new to the forum, so I thought I'd just jump right into posting! I love your username by the way! Anyways, in my opinion it wouldn't logically make sense for an intruder to write a ransom note either and leave the body in the home.
If an intruder wrote the note then he or she wasn't too sure why. The writer originally wrote out "The two gentlemen watching over your daughter do particularly like you," but then the word "not" was carrot-ed in between do and particularly. I will go ahead and point out that as a journalism major, we use this particular revision sign a lot when editing and given that PR was also a journalism major the use of that editing symbol is a red flag. Why would someone motivated enough for the crime make this mistake? The end of note also establishes a hateful tone towards JR, so again why is this mistake made if such strong emotions are present? In addition, the intruder makes the mistake of writing delivery of JB and then crossing it out and writing pick up. Again, making this mistake wouldn't make much sense either if an intruder wrote the note. I also want to include that the study pf journalism applies an emphasis on mastering how to appeal to various kinds of audiences and evoking ideal responses...
I won't continue on with my own take on the ransom note unless someone is interested, but if an intruder did write the note then it shows that they weren't very invested in the crime or that their own intentions weren't very clear to even themselves. This finding would clash with the fact that their were no points of forced entry found nor any fingerprints or noises heard by the family. IMO, that would mean the intruder would have to have been very prepared and that the crime was premeditated. The intruder theory just leaves me with more questions than answers. As much as I don't want to believe that someone could hurt their own child, it happens every day and I do lean towards someone in the family being involved.