IamFreeCanIGo
Banned
- Joined
- Oct 14, 2013
- Messages
- 165
You're mistaken. Fifteen of nineteen alleles present is not a match, with her profile (having the double and that number of loci) nineteen of nineteen is. Fifteen of nineteen might still indicate that person contributed to the sample, but you'd have to allow for four dropouts which happens with low template DNA analysis but it isn't a very encouraging sign being as there's a minimum of three contributors to the sample and they'd have to fail to pick up those alleles from there as well. All factors considered (number of contributors, the fact the parents accessed that trunk, the nature of LT/LCN DNA and that something of the victim might have been placed in the trunk) it by no means could be considered 'strong' and the best the results could be described is 'irrelevant.'
You do realize that with a mixed sample with three to five contributors you could match 19 of 19 and that person still didn't contribute to the sample? With the parents (and a sibling?) also being likely contributors (meaning roughly half the alleles would be a gimme) that would not be as unlikely as you might think.
These results are meaningless. Strangers can share a number of alleles and the more contributors the more possibilities you can piece together a profile from strangers for a person who didn't even contribute to the sample. In another case the victim, whose parentage was British/Indian and the killer, who was from sub-Saharan Africa between them share ~eight alleles with a third man who is from Italy. A sample with the victim and the killer and 1-3 others could very well put together ~75% of the profile of the Italian who didn't contribute.
When you're working with low template mixed samples two of the normal ways of excluding someone are nerfed or eliminated. Normally with a high template single-contributor sample an allele that does not belong to the subject would exclude him, you can't do that with a mixed sample as that allele could have been one of the other contributors. Usually drop out (with non-degraded DNA) is fairly rare, with low template it's more common meaning even if the alleles aren't there you have to take into account the possibility of all the missing ones having dropped, which is a damned sloppy way of getting a match!
What this means is you, I and everyone on this thread couldn't actually be excluded from having contributed to the sample. Some would have a higher statistical weight of evidence than others, but there's no actual way of excluding someone completely. Also due to the nature of low template mixed samples there's the fact that you're dealing with trace DNA of numerous people and you know they weren't all stuffed in that trunk! Trace DNA transfers far easier and if anything that toddler had touched, or someone who touched that toddler put something in that trunk it may well have transferred that way, so even if they'd found a full low template profile there's no way of determining how it got there and many plausible ways it might have.
I've not followed this story so I am uncertain as to the relevance or probative value of the former, but including the latter is not suggestive of anything, and the little I have learned about this event actually more indicative of having nothing to do with the disappearance of the toddler. Those DNA results are worthless and including that in your summary doesn't help your case.
The dog barked and...huh? Just whose police force thought a coconut was a skull? Are they...the same ones who you're relying on for any evidence or theorizing?
Thanks for the info mate. You seem to know your stuff regarding DNA, what are your qualifications (not saying that to suggest you are wrong, just interested, if you are qualified in the field id like to ask you some questions and you seem to be pretty qualified from how you write.)
What you are saying would clear up a lot of questions regarding the dna evidence, why do you think the PJ used this evidence to make the mccanns suspects if the evidence was so worthless?
