The results Boulder Police used the DNA results for the panties and fingernails DNA obtained by CBI in January 1997 for elimination of people as suspects in a most inappropriate way, possibly enabling certain people to 'slip through the net'.
In looking at the results for the panties bloodstains, it can be seen that there was only one allele, allele B identified at the GC locus.
There were also five alleles in total that were identified in the DNA under the fingernails. The fingernails DNA at the GC locus also had the B allele.
So, while the fingernails DNA and the panties bloodstain DNA could not be said to be a match, neither were they a mis-match. It is possible the fingernails DNA came from the same person whose DNA was in the panties bloodstain. It is possible that it didn’t.
Nevertheless, Boulder Police went ahead and assumed they did match. They were quite wrong to assume this but seemingly they did so because it enabled them to eliminate a lot more people as having contributed to the panties bloodstain than if they had only been able to rely on the one allele that was identified in the panties bloodstain.
If Boulder Police had only relied on that one B allele identified in the panties bloodstain, they would only have been able eliminate 78% of the people they tested, leaving an inconvenient 22% that they would not be able to eliminate. However, they did not use just the panties bloodstain DNA to eliminate those whose DNA might have been left there. They also used the fingernails DNA to eliminate people whose DNA might have been left in the bloodstain. this was a major error and to my knowledge has never been addressed
Curiously, at the same time Boulder Police were eliminating people using DNA evidence found under the fingernails, they made it known publicly that the DNA under the fingernails was likely due to contamination.
Boulder Police wanted it both ways – they wanted they wanted to be able to eliminate as many people as they could as having contributed to the panties bloodstain DNA while at the same time wanting to say that the fingernails DNA was likely not connected to the crime at all. Good one.
As Barry Scheck said at the June 1, 1997 meeting in relation to what the police were doing with respect to eliminating people with the CBI DQA1/PM results obtained January 15, 1997:
“You can’t say the DNA test results are iffy and then exclude people because their DNA doesn’t match. You can’t have your cake and eat it.”