By the way Roy, in reading your signature paragraph:
The discovery of additional matching DNA in the JonBenet Ramsey murder case is important information that raises more questions in the search for JonBenet's killer. The BPD concurs with the Boulder District Attorney's Office that this is a significant finding. The PD has continued to look diligently for the source of the foreign DNA, and to date, we have compared DNA samples taken from more than 200 people. Finding the source of the DNA is key to helping us determine who killed JonBenet
I present your killer. (Cynic, this is great enough to post one more time!! Thanks):
8. The Mixture Theory:
Full siblings born to unrelated parents have identical STR profiles at an average of four of the thirteen CODIS core loci, compared to, on average, identity at less than a single locus among unrelated individuals. My data set included a sibling pair with identity at nine of the thirteen CODIS core loci, and another colleague has informed us of an eleven locus match in a brother and sister.
DNA and the criminal justice system: the technology of justice by David Lazer
Despite having seen this bit of information before relating to the panty bloodstain, which ultimately was also found to contain a 9 ½ marker intruder DNA profile, its full significance never occurred to me.
The DNA profiles developed from exhibits #7, 14L and 14M revealed a mixture of which the major component matched JonBenet Ramsey.
If the minor components from exhibits #7, 14L and 14 M were contributed by a single individual then John Andrew Ramsey, Melinda Ramsey, John B. Ramsey, Patricia Ramsey, Burke Ramsey, Jeff Ramsey, XXXXXXXXXXXXXXX and XXXXXXXXX, would be excluded as a source of the DNA analyzed on those exhibits. (By way of explanation: #7 refers to bloodstains from panties. #14L,#14M are right and left hand fingernails from JonBenet Ramsey.) (From a lab report held up by Erin Moriarty on "48 Hours Mystery)
[ame]http://boards.library.trutv.com/showthread.php?t=290578[/ame]
I always looked at this as saying that there was a mix of JonBenets blood and an unknown male DNA minor profile, in other words the mystery intruder profile.
While true, I overlooked the other possibility which is clearly spelt out:
If it is not a single contributor then a DNA mix involving two of the following people: John Andrew Ramsey, Melinda Ramsey, John B. Ramsey, Patricia Ramsey, Burke Ramsey, and Jeff Ramsey may be what produced the minor profile and not an intruder after all. (At least one of the two people would have to be a male, as there is a Y marker present) This means that the DNA found in the panty blood stain could simply be a mixture of JonBenets blood cells and skin cells from JR and PR as one example.
To illustrate, consider the following very simplified 5 marker profile:
JonBenet (5,12), (8,9), (3,3), (6,4), (9,12)
Patsy (5,8), (7,9), (4,3), (6,11), (9,5)
John (3,12), (8,10), (3,6), (8,4), (7,12)
(Note that because I am using JBRs parents in the example, JBR is receiving one allele from JR and PR at every marker)
The mixed profile from this example found in the bloodstain would be:
(3,5,8,12), (7,8,9,10), (3,4,6), (4,6,8,11), (5,7,9,12)
You then remove the victim profile and are left with the following alleles to explain:
(3.8), (7,10), (4,6), (8,11), (5,7)
The lab is saying that there are two possibilities:
There is an unidentified male with the following profile responsible for DNA found in the blood stain: (3.8), (7,10), (4,6), (8,11), (5,7)
Or, it was from a mixture involving family members.
Clearly it appears that the DA chose to believe that it was an intruder rather than a Ramsey family member.
The following is one possible explanation of how the mixture happened:
John Ramsey breaks a paint brush previously used by Patsy and containing her DNA. The portion of handle now containing both his and Patsys DNA (skin cells) is inserted into JBRs vagina causing a small amount of bleeding. The size 12 panties are put on, and JBRs blood mixed with JRs and PRs DNA is deposited. JR pulls up the long johns which PR admittedly handled earlier and once again a mixture of their DNA is left behind.
The Bode lab simply found and declared a match to the same mixed profile found in the panty underwear sample.
Just to be clear, some may be under the impression that touch DNA from the long johns is the crucial DNA in this case. That is not true. The partial profile in CODIS from the DNA in the panties is the foundation. All other DNA will continue to be compared against that partial profile.
If that profile is wrong because it is merely a blend of alleles from Ramsey family members (probably just PR and JR), then it completely invalidates the intruder theory, at least insofar as support from DNA tested to date is concerned.