The Ramsey's paid John Douglas, a well respected profiler, to interview them to prove that no one in the family killed her. Its in the book, The Cases that Haunt us.
Author:
John E. Douglas;
Mark Olshaker
Publication date: 2000
I never thought it was the parents or the brother. What I do think is, someone who knew / knows the family did it. Someone who knew that her father got a $ 118,000 dollar bonus. Also, the partial DNA doesn't match anyone in the family.
“The match of male DNA on two separate items of clothing worn by the victim at the time of the murder makes it clear to us that an unknown male handled these items.” I know that there are some disputes to this however, they are unproven.
I think they need to DNA swab everyone who worked for her Dad, the neighbors , anyone who worked for the family, males who attended the pageants ( father's of other girls, etc. ), people who worked on the house and all other male family members. It is someone no one expected. Just my 2 cents.
This person was stocking her for a while. Also, notice it happened during Christmas time which seems a bit punitive to me. Someone who wanted her and who also had anger / Jealousy towards the father. Both. She ate pineapple without screaming because she knew the guy. Unfortunately in these cases, its someone no one every thought would be the guy and was never suspected.