No little to nothing about DNA but in a court of law, it can exclude as in this case. Funny, we heard early on that there was other DNA present and the boyfriend was "suggested". So, there must have been a "leak" which sent the Defense "back to the lab". It's the timing of everything that matters. It's why they were indicted in the first place. DNA was NOT the grounds for the indictment. So, what was??
It's possible they just did good, skeptical, lawyering, knowing who they were up against. When they got the report, they immediately requested the back-up documents. Nifong fought them on that issue and they had to get the judge to order him to have the lab produce them. Going through the back-up documents they found this little surprise.
This case has the potential to cause a lot of distrust and lack of confidence in our legal system generally, on the part of tens of millions of Americans. But how many are even paying attention? Has the MSM given any attention to the latest developments? I get most of my news from FR and FNC...the brief times I have switched to one of the enemedia stations they are on some other topic.