10 August 2023

DNA GENEALOGY and THE BRYAN KOHBERGER MURDER CASE : IS THE DNA ENOUGH? CAUTIONS ON THE USE OF DNA SERVICES

DAILY MAIL UK - KOHBERGER IDAHO TRIAL UPDATE 

I've been following this murder case, perhaps uncharacteristically so, since the four college students in Idaho were found stabbed to death in their close-to-campus rental house late last fall.  Bryan Kohberger, a graduate student in criminology at another university across state lines but only about 20 minutes away by vehicle, was arrested as the only suspect about a month later.  The crime-investigation buffs all over the world, including several who run crime-oriented YouTube channels immediately got interested in the case. My concern was and is that almost everything I have heard and read has him guilty before being proven so.  Can he get a truly fair trial?  I read that there have been over 40,000 articles and videos about him and even those that have people who should know better - such as FBI agents and police detectives - talk about him as if this were so.

It's IMPORTANT.  Any of us could be arrested for a crime we did not commit and lack the resources for our legal defense.  Any of us could be falsely accused of anything. So this is a test case for what happens in today's world of easy information and world wide coverage.

Meanwhile there are literally many thousands of unsolved murders in the United States that get no attention. 

Bit by bit his defense attorney or his defense has provided information that would indicate that Kohberger may very well be innocent of the crimes. Seems as if a tiny bit of DNA that was taken off the metal button of a knife sheath left at the scene is now being refuted.  The party house, one in which parties went on when none of the renters were there to host or keep control, was one in which strangers could easily attend. DNA from others was found there. In addition, there was reported (and i can't verify) that despite what was said to be an extremely bloody scene, no blood evidence was found in Kohberger's apartment, car, or parent's house...

In the article above, which I'll excerpt from below, the difficulty of being sure of results is stressed.

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Excerpt:

A poor quality kit might have too few matches or it just might have phantom matches that are not real measures of relationship,' the document reads.

Larkin notes that sites such as AncestryDNA, 23ndme and MyHeritage prohibit forensic/investigative genetic genealogy in their databases, but there isn't really a way to enforce it.

'In the absence of effective oversight, forensic genetic genealogists are on an 'honor system' to obey the Terms of Services and the Department of Justice Interim Policy on forensic genetic genealogy.'

Larkin explains that the science used by these sites is not perfect, and 'any given centimorgan amount can represent more than one possible relationship.'

She notes one example that has nearly 20 possible relationship lines listed for a match - and says that's considered a close match.

Larkin points out that unlike DNA tests that find an individual, which are standard forensic STR tests, genetic genealogy testing identifies possible relatives. 

She then goes on to note cases she's allegedly aware of where genetic genealogy has been wrong, as well as cases where the databases were used improperly by authorities.