As far as the lab techs being "sure" they found the DNA of the killer- unless they were also eye-witnesses to the killing, NO ONE can say it is the DNA of the killer. It is the DNA of someone other than JB or her family. That is all. Even if that DNA belongs to someone who was in the house that night, intruder or not, that doesn't mean they were in the room when she was killed or that they killed her. That DNA doesn't place someone at the scene of the crime (her death, not the house) because it is not found anywhere else at the scene. Only on her clothes, NOT on her body, doorknob, suitcase handle, paint tote or paintbrushes, tape, garrote, white blanket, etc. Speaking of the blanket, someone involved with the crime had to have pulled that blanket over her AFTER she was dead. If they left DNA on the clothing, they were NOT wearing gloves. I doubt they'd wear gloves to wrap her in a blanket and not wear them as they actually handled her body or killed her. If it is on the blanket, then it brings the DNA into the crime scene. While it is only on the BODY, it may have been left while she was alive, and as PATSY says, if JB put those huge panties on herself, the DNA may not have had anything to do with the crime at all.
Here's a thought- let's say that JB was awake when she got home, not asleep. Let's say that she dressed herself in both the panties and the longjohns. After all, the parents' DNA was not mentioned as being found on the longjohns, though both parents said they touched them (Patsy when she claims to have put them on a sleeping JB and JR when he carried her body up from the basement). So let's say for argument's sake that she dressed herself. IF that DNA found its way onto her hands at the White's, that is a plausible explanation, IMO, for the DNA to be found there and no where else at the crime scene.
BBM: That is such a good point. I have always believd that if IDI, he/she was wearing gloves the entire time for your reasons stated above. I have a question: Touch dna from my understanding is from shedding skin, but is it possible one could recover "touch" type DNA from saliva or say, from the arm past the wrist where the gloves might not have been? Just curious.
Also someone pointed out on this thread that the touch DNA could be from any of the male children around at the time, whether at the party or at the home. If they were tested now and matched, I would be entrenched in the RDI scenario so fast. I wonder if they were or ever will be.
ETA: I completely discount ANY dna found from the fingernails. Those clippers were not sanitized and could have come from anyone... any other body from the coroner's office.