The thing is, it <i>is</i> possible to distinguish samples of DNA in mixtures (and it can work fairly well). But the technique they used to do so was outdated and no one particularly bothered to find how well it worked. I mentioned in my comment above that their misstep was only applicable to &quot;mixtures&quot; and that DNA analysis as a whole still makes sense.<p>I would not extrapolate the error in the headline across the entirety of NPR, though. The reporting in this article was factual and (AFAICT) unbiased. Although I believe that &quot;soft sciences&quot; as opposed to &quot;hard sciences&quot; exist, and that NPR can be biased (they have been in the past), I do not believe this discredits NPR entirely. The mistake they are reporting allegedly affects thousands of cases. That statement is unlikely to be a result of bias.<p>It is very hard to prevent bias at the publishing outlet level (and very easy to introduce it). I recommend that people get their facts from a number of sources and that they listen to every opinion they can find.