Snipped by me--I don't think this is accurate.
@Balthazar agrees the defense has not contested the actual match of the dna on the sheath to BK's dna. To my knowledge, the defense has never said the dna on the sheath is not BK's. It's his. There are no known issues with the retrieval, processing, matching, etc. of the dna on the sheath. The defense has likely done their own testing and if it didn't match, we'd surely know. To keep saying there's a problem with the match is inaccurate.
The filing you're citing is in regards to the Investigative Genetic Genealogy, the IGG. The defense is not really disputing any scientific process. They want to see the paperwork done by the FBI (and it's the FBI who had not turned over what the defense was asking for, not the prosecution) and the FBI was resisting, saying it wasn't material to the preparation of the defense and not subject to discovery.
The defense spends a lot of time in this motion arguing that they want to see the work product because it could be wrong. They argue that the IGG could produce a pool of suspects rather than just one and they want access to the tree created by the FBI. This argument is kind of disingenuous though. The IGG is easily replicated. There's no scientific process involved once you have the dna profile (which the defense doesn't dispute). They admit they've done their own IGG and created their own family tree. They already have the pool of suspects the FBI has and could (and likely have) investigated them on their own. In the cases they cite, the pool of suspects were tested and ultimately matches were found. For example, in the Angie Dodge case, they initially narrowed it down to one suspect, he was tested, and didn't match. It was a tip that didn't pan out. They went back to the tree and looked for other suspects to test. This is why the FBI calls this an investigative technique--IGG generates tips, places to look, but ultimately the match must be made.
If the IGG in this case was "wrong"--if it was done incorrectly, if there wasn't enough to provide matches, if the matches really point to someone else--the dna on the sheath would not match BK. And the defense doesn't dispute that it's a match. The IGG was right. So why were they fighting it so hard? The real reason is in this portion of the filing you cited:
"In addition, there has been a history of misuse of these IGG databases by law enforcement. Abuses by law enforcement of the GEDMatch resulted in users opting out of the use of their DNA data by law enforcement. The abuses and protests by users led GEDMatch to change their database so that users had to opt in for law enforcement use."
The defense wanted to see the work product of the FBI because they wanted to see if they violated any terms of service of these public databases when generating the matches and creating the family tree. This was their only hope of somehow getting the dna thrown out. Because it's his and they know it.
IMO