according to a forensic scientist on ch 4 news regarding the maccan case an 80% dna match indicates 18 0f the 20 markers used in analysis are the same,if that is the case what percentage of a dna match would 9 markers be?thanks.
I believe to deposit the DNA of an individual does not require the physical prescence of that person. Mrs McCann has been carrying Madelines cuddly toy around with her wherever she goes. I have read its possible to transfer DNA via this method. If so I feel badly let down by this science as it can easily be copied by others.
Far too many people have too much faith in DNA evidence.
Whatever you might think about OJ Simpson's guilt or innocence the defence did a fine job of tearing the DNA evidence into tiny strips.
in that case PCR (Polymerase Chain Reaction) was used to reproduce small quantities of DNA into a large enough sample to test.
So you don't actually work with the original material - if it's badly handled (and it was) you can get spurious results
It's a very good tool but personally I'd always be suspicious of convictions that relied soley on DNA evidence without other forensic or witness evidence to back it up.