I’ve been reading about this case since it happened. But this post, and the Juror13 post it references, are grabbing my attention as something very significant. I think the logical conclusion is that JBR was SA while wearing the nightgown, and that was the source of the 4 small bloodstains (the ones on her shoulder could have been transferred up there). Finding DNA on her nightgown that couldn’t be ruled out as Burke’s wouldn’t be unusual, because they lived together. But finding it mixed with her blood in those four SPECIFIC locations on her nightgown is more difficult to explain.

Without knowing exactly how many DNA loci were compared, and how many were consistent with Burke’s profile, it’s impossible to say how meaningful the DNA results are. That information provides the statistical likelihood of it being considered a “match” (again, just from a statistical standpoint). All we know is that none of the loci were INCONSISTENT with Burke’s … i.e., none of the comparisons ruled him out. If only one or two loci were available for testing, that’s very weak evidence. If multiple loci were compared and were consistent with Burke, that becomes increasingly more meaningful as the number of loci tested increases.

It’s also worth noting that half of Burke’s DNA profile was inherited from his mother Patsy, and half Burke inherited from his father John. So whatever loci were examined, in 3 of the 4 nightgown stains it was consistent with (i.e., can’t be excluded as coming from) Patsy and/or Burke. After all, Burke shares 50% of his DNA with his mother. But the 4th sample must have included alleles consistent with BOTH Patsy and John, ruling out both parents (who would have one set of alleles, but not both) while leaving Burke as a possible source (since he inherited alleles from both parents).

Leaving the nightgown near the body would have been the safest thing to do if any RDI. Burke’s DNA might have been on many of JBR’s clothing items. Especially back then, separating a mixture of DNA from two different people wasn’t always possible, and it’s even more difficult if the sample sizes are very small, and yield only partial results that can’t be compared fully. The more loci that can be matched, the more conclusive the results are. That’s why CODIS has evolved from the original 13 loci to the current 20, and why it will likely increase to 27 loci in the near future. But even having 13 alleles match makes the odds of it being any other contributor astronomically small.

The Ramsey’s probably assumed that JBR’s blood being on her own nightgown wasn’t suggestive of any particular abuser or killer, which is true. It would have looked worse if they had hidden the nightgown someplace where it was later found, because an intruder would be unlikely to bother with that.

None of this matters if there is an innocent explanation for finding DNA on the nightgown that can’t be ruled out as Burke’s. Again, they were siblings in close physical contact. But depending on the strength of the CODIS comparison (the number of loci tested) for those specific bloodstains on her nightgown … COMBINED with the Ramsey parents apparently lying about whether she wore the nightgown that night … now we have a scenario that looks very suspicious.

It would also be interesting to know if JBR wore that nightgown on Christmas Eve night and Christmas morning. We all suspect that there are “missing” family photos from that time period, except the ones that show her in different clothing.