One of my former professors has done a lot of work on the issue of how DNA evidence is presented to juries. Basically, when you quote the Random Match Probability, jurors (and apparently journalists like the author of the article) basically forget about everything else: http://bioforensics.com/conference/RMP/RMP%20-%20irrelevant.....
There's two different logical errors involved. First, jurors conflate proving the assertion "this is the defendant's blood" with "the defendant killed the victim." Second, the "one in a billion" theoretical random match odds turn into more like "one in several thousand" when accounting for laboratory error. In fact, laboratory error totally dominates the error rate of the overall process.
There's two different logical errors involved. First, jurors conflate proving the assertion "this is the defendant's blood" with "the defendant killed the victim." Second, the "one in a billion" theoretical random match odds turn into more like "one in several thousand" when accounting for laboratory error. In fact, laboratory error totally dominates the error rate of the overall process.