Excuse me if a similar theory has already been posted, I haven't visited in awhile.
Based on my readings of the case over the years, I come to the realization that most people think the killing and ransom note go hand-in-hand. Meaning, the killing and note were done by the same person: Parents(as one) or Intruder.
What if the parents merely discovered her dead body and panicked, thinking they would be blamed?
The intruder would have to of been a sexual predator, who either snuck into the house when they were gone, or came in when everyone was asleep. Breaking in with the house empty is safer.
We know for a fact, however, that she was not raped. A 6 year old raped by a grown man would have been quite obvious to the medical examiner. So something stopped him from getting that far. Who here knows how to make a garrote? A very good one at that? I certainly don't. That wasn't something that was just whipped together. The maker made many before. So if an intruder didn't do it, then there is no other conclusion but to say she was sexually abused by her father. In a very sick way.
So the intruder is using it on her, at the same time maybe just touching her. He doesn't realize how hard he is strangling her or maybe he leaves the room. Comes back and finds her asphyxiated. Out of sexual frustration and all his vain hard work, he smashes her in the head. I don't know how many pedophiles are also necrophiliacs. This could have been done in the kitchen or living room.
How did he leave? I don't know what type of locks they had on their doors, but perhaps he simply walked out the front door.
Patsy comes downstairs and finds the body. The Parents freak out and write the ransom note. This seems crazy, but none of us know what we would do until that situation presents itself.
Her body was also cleaned, new clothes even, and hair combed. She also had a blanket on her. In fact, you could say she was "tucked in".
That sounds like something a mother would do. Not something an intruder does in the victims house.
Whatever your view is, there is one piece of evidence that is clear to anyone with eyesight: Patsy wrote the ransom note. There is no other way around it. Some of it from her own mind, the rest dictated by John. Written with both hands. The words that look disguised were probably by her left hand. Her letters were so exact it made my body tingle. Almost a dozen experts saying without a doubt it's Patsy's handwriting is good enough for me. I can't believe they didn't arrest her on that alone. Not enough evidence you say? I think it is.
Patsy wrote the note after one of the following 3 scenarios.
1.After she was killed on purpose.
2.After she was accidentally killed.
3.After they found her dead body, and were afraid of being accused, so they concocted the note, which is paradoxical in hindsight seeing as how it pointed right to them.
About the Pineapple:
Who's to say she wouldn't follow a stranger down the stairs? A family friend would have an even easier time. Prepared it before he went upstairs, then force fed her. He could have needed more time, so he kept her busy. She and her brother could have gone into the kitchen before bedtime without anyone knowing. All are possibilities.
BTW,
I think 3 is the most unlikely, but the easiest to accept. It puts all the evil deeds in the hands of the evil person.
As for number 2, you can go ahead and substitute "John" for "intruder" in my post. I don't see her being killed on accident, for wetting the bed or whatnot, then all those cruel things done to her to cover it up. Then again, she was strangled first, so that would mean that is how she was punished.
1 is the absolute worst. The only explanation for "murder", is she was tortured to death.