There is a great deal of discussion going on around the 'net regarding the Ramsey case DNA. I believe it needs revisiting and too much is being 'said' without much substance.

These are excerpts from PMPT and JBITRI to refresh everyone's memory as to WHAT has been said in the two most often (mis)quoted books. (Please add any other excerpts you may have.)

PMPT pb p 182
"During the same week (note: Jan 1997), the CBI discovered that the stain found on JonBenét's panties contained the DNA of more than one individual. JonBenét's DNA was the major component, but there was a minor componenet consisting of DNA from another person - or possibly more than one. The CBI told the police that the Ramseys' neighbor, Joe Barnhill could not be eliminated if the minor component originated from two or more sources. Further testing would take several months, the lab said."

The CBI tests were PCR (PMPT pb p240) "The CBI had already (note: prior to Feb 1997) determined that the stain on JonBenét's underpants ... was not solely hers. A D1S80 DNA test showed that the stain came from at least two different sources. {Footnote: A D1S80 test is a PCR-based test that measures the genetic marker known as D1S80 on the DNA strand.)"

Then the evidence was transferred for further examination to Cellmark. (PMPT pb p227) "Test results can take from several days to weeks using the PCR method of testing, RFLP typing takes months. In some cases it can take up to ten months to obtain test results because the lab is so backlogged.

ST - JBITRMI, pb p204
"When the preliminary DNA results came back from the CellMark labs, .... That early report was very ambiguous. We would get a more thorough briefing in five months and would hold this early material as confidential." (note: confidential as in out of the hands of the DA's office)

p 298-300
The detectives had consulted a couple of experts in an attempt to answer four questions concerning the DNA issues: What did we have? What did it reveal? Where do we go now? Would DNA solve this case?

A special briefing by molecular biologist Melissa Weber of Cellmark Laboratories and Kathy Dressel of the Colorado Bureau of Investigation provided no miracles. The results remained frustrating and ambiguous, and even the experts did not agree on everything. Among their findings was that the DNA might not be related to the murder at all. Other results were open to interpretation.
· A head hair found at the scene appeared to belong to JonBenét.
· The primary DNA from the panties also appeared to be from her. But a secondary DNA source may have been present. If that secondary material was a mixture from two or more people, then the labs could exclude no one. Faint DNA results may have been due to “technical or stutter artifact.”
It might be as simple as JonBenét having put on a playmate’s underwear in which foreign DNA already existed. On the other hand, the mixture that had been found was complicated by a myriad of technical factors, including quality, quantity, degradation, and possible contamination. That meant that excluding people might be possible, but positive identification was unlikely.
· The fingernails of the left hand presented uncertain technical issues. JonBenét appeared to be the primary DNA source, but the experts could not exclude any male as the donor of a secondary source that was present. Issues included the possibility that multiple DNA had been under her nails for several days.
The experts noted no blood or skin tissue beneath the fingernails, as they often see when a victim has fought an attacker. However, DNA can be deposited by someone merely dragging their nails across their own cheek.

(comment: Big contradiction here – dragging one’s nails across one’s cheek would result in what type of cells under the nails? SKIN CELLS! I believe Steve has spun his own interpretation on the DNA evidence. If the foreign DNA under JB’s nails was not from blood, not from skin, WHAT was it from? If it were semen, we’d have heard about THAT! It COULD have been saliva. Even if the foreign/unknown DNA was from an innocent encounter, it HAD to be from saliva, blood, skin, or semen.

With regard to the “complicated technical factor” of “quantity”, that would only be an issue for RFLP testing, not PCR testing. I think Steve really had trouble following, interpreting, and reporting on what the “experts” were saying.)

· The fingernails of the right hand were equally ambiguous, with JonBenét again appearing to be the primary donor and once again an unidentified secondary male DNA present.
· They drew no firm conclusions regarding the pubic hair. It was deemed, however, that it might not be a pubic hair at all but possibly a hair from a chest or beneath an arm. That would confuse things even more.

We would later discuss the cleanliness of the victim, including not washing her hands, wetting the bed (comment: no DNA concern with that), not wiping thoroughly after a bowel movement, (comment: no DNA concern with that), and hating to have her fingernails trimmed. Weber said that the DNA beneath the fingernails could have come from anywhere, particularly if it had been there for several days, and that degradation was a concern.

They explained that obtaining additional DNA samples from any new suspects would not necessarily assist in identification. (comment: only partially true) Because of the possibility of mixtures from more than one source, conclusive determinations could not be reached. (comment: Steve’s interpretation leaves much to be desired. What does “conclusive” mean? Odds of 1 in X trillion would be pretty conclusive – and that would be the result of a 13 CODIS-specific loci MATCH. Odds of 1 in X millions would be pretty conclusive – and that would be the result of a less than 10 marker MATCH.)

Their results could be argued a number of ways, and defense lawyers surely would say that any unknown DNA found came from an intruder, although in fact hardly anyone could be excluded. (comment – Now here, I know for sure, Steve is WRONG. Exclusion is the easiest result to get.)

We could not determine whose DNA it was, when it was deposited, or if it had been degraded. (comment – WHAT? All along there have been clear statements from posters that have been saying it WAS degraded DNA!)

With those inconclusive findings, the district attorney asked Henry Lee if he would “unravel the DNA mess,” and Lee refused, suggesting that the FBI lab do that. “Adequate and complete testing should have been done long ago,” he scolded.

Hunter then asked what we should do to solve the case and Lee replied that he was only a scientist who could advise on evidence collection, testing, and results. Figuring out what it all meant in the company of other evidence would be somebody else’s job. “This case,” he said, “will be a war of experts.” (comment - hmmm. Still looking for that "this is not a DNA case". Sounds like Lee thinks it could be since he suggests the case will be a "war of experts".)

Trying to sound optimistic at a news conference later, Lee told reporters our chances had risen to fifty-fifty.
(comment – How do you interpret that? I interpret that Lee sees the DNA evidence as RAISING the odds.)
~~~~~~~~~~~

DNA testing has come a long ways since 1997. Dr. Henry Lee’s Interpretation of Complex Forensic DNA Mixtures <1> states: “Forensic evidentiary samples routinely contain DNA from multiple contributors. The interpretation of these mixtures can be a challenging task for the DNA scientist.” He then discusses “Several approaches which have been employed to assess the significance of an inclusion/match when DNA mixtures have been detected in casework samples.” These points Dr. Lee discusses include some of the points Steve Thomas mentions, but concludes “The process of mixture interpretation can be relatively straightforward or quite complex, involving laboratory and statistical considerations. While many of the technical challenges are routine features of forensic laboratory analysis and therefore cannot be eliminated, use of conservative statistical methods should obviate court objections and reduce the difficulties in mixture genotype assignment.” THIS IS IMPORTANT!!

<1> Interpretation of Complex Forensic DNA Mixtures, Carll Ladd, Henry C. Lee, Nicholas Yang, Frederick R. Bieber

DEGRADATION: “The breakdown of DNA into smaller fragments by chemical or physical means.”