A few myths and falsehoods get repeated here about the DNA evidence, seemingly based on a partial and ambiguous understanding. "Partial and ambiguous" was a phrase used by a defence legal consultant, Ms. Bicka Barlow, and is taken out of context. Ms. Barlow was clearly discussing another, historical case - Hernandez, in the preceding three paragraphs of her affidavit and indeed within the same paragraph where the "partial" phrase is used (link to full document from Idaho Courts, link opens PDF)

Page 12/ 13 of Ms. Barlow Affidavit 06/23/23

The reasons this does not and cannot relate to the Kohberger sheath DNA are:

• Ms. Barlow discusses analysis of a mixed DNA sample (multiple DNA profiles) - the sheath DNA was not a mixture
• She discusses multiple matches in CODIS based on a partial profile uploaded to CODIS; the Kohberger sheath DNA returned no matches in CODIS (known from defence filing 06/22)
• She discusses 5 to 28 candidate matches from this partial, mixed DNA sample; there are not 5 or 28 candidate matches for the sheath DNA
• She terms these candidate matches from CODIS as Brady material (exculpatory evidence withheld from defence) - obviously as she has all the info on these candidate matches they cannot be Brady issues in the Kohberger case; as there are not 5 or 28 (or any) actual or potential CODIS matches in the Kohberger case these cannot be Brady materials in this case
• She discusses the subjective nature of mixed DNA sample interpretation as the source of ambiguity - the Kohberger sheath DNA is not a mixed DNA sample

A minor observation - Ms. Barlow's affidavit is dated 2020 - the date comes immediately after the Hernandez case discussion section. A small speculation: was that section copied/ pasted from an earlier affidavit/ document pre-dating the Kohberger case?

2020 Date of Barlow affidavit

Old Cabbage

While not undermining Ms. Barlow's legal expertise, she is not a scientist and has never worked in the field of human DNA science (or indeed in any scientific field). She has only ever published one scientific paper in a peer reviewed journal, which was on cabbages and is from 1989, pre-dating the widespread use of DNA forensics. While vegetables, especially root vegetables and tubers, are very important to the Idaho economy, undergraduate cabbage biology research may not qualify one as an expert in human DNA forensic science, biochemistry of human DNA manipulation or molecular biology.

DNA Profile Match Statistics

As many independent experts have noted, the match statistics of the direct comparison of the sheath DNA to Kohberger via cheek swab are over-powering and impossible without a full profile. DNA "matching" or profile comparison looks at 20 non-coding "areas" within the human genome - the statistics here indicate a match of all 20 "areas" from a complete DNA profile. Within the last 10 years LE forensics had used 13 STR "areas" and a match of all 13 was considered a statistically very robust match - here we have a match at all 20 loci. The random match probability in this case is that the sheath DNA is 5.37 Octillion times more likely to be seen if Kohberger left the DNA than from a randomly selected individual. 5,370,000,000,000,000,000,000,000,000 x more likely. The general probability of two unrelated Caucasians having identical STR DNA profiles is approximately 1 in 575 trillion.

The match certainty of Kohberger's DNA to the sheath is millions of orders of magnitude higher than the match certainty used for the award of Nobel prizes for genetic cloning research, verification of life and death cell line based medical treatments, and legal paternity definition.

Touch DNA - Quantity and Quality of Sample

Even if the sheath DNA was "touch" this does not equate to a borderline or marginal/ nominal quantity of DNA being recovered meaning a less robust profile, as is often suggested here. The generation of a complete DNA profile from touch DNA requires 20 - 200 time more cells than a DNA profile from cheek swab.

"Touch DNA" can contain sweat, saliva and sebum and other fluids from the DNA donor, as a major or the major source of the DNA, so the idea that it was just a few dead skin cells on the sheath is flawed. The fact that a full, complete STR DNA profile and an SNP profile (a different profile type used to search genealogy databases for relatives) was generated also indicates a more than sufficient, ample quantity of DNA was recovered.

https://www.fsigenetics.com/article/S1872-4973(20)30225-8/fulltext30225-8/fulltext)

Forensic Science International - Genetics: Volume 56, January 2022

Defender's fallacy - even if the match statistics were billions of times less robust than the 5 octillion, as an example at 1 in a billion, it would mean that out of the global population there might be 2 people expected to match the STR DNA profile. What are the chances the other person, out of the whole global population, would drive a white sedan in a cul-de-sac in Moscow, Idaho at 4.00am in the winter of 2022?

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