The Best Uses for DNA: The Duke Case Continued

Another statement I disagree with from the original article:

The best use of DNA is excluding someone as the source of a particular sample," said Mark Rabil, a Winston-Salem lawyer who represented Darryl Hunt, a man freed in part by DNA evidence after serving 18 years in prison for a 1984 rape and murder.

I recoil at the use of the term "best". If DNA, as it currently existed, were "best" used as an exclusionary technique, then we could get by with a simple test that either said "match" or "no match". All of the statistics and studies of DNA profile rarity would be unimportant.

I won't belittle the benefit DNA has had for the wrongly convicted, but we shouldn't throw out the baby with the bathwater either. The primary benefit of forensic DNA technology as it exists today is not finding out who doesn't match the evidence, but understanding what it means when someone does match the evidence. The statistics that tell us that a profile is so rare it is found in only one out of ten trillion Caucasians allow us to interpret our results with confidence and present them honestly. We can then make intelligent statements about what fits best with the evidence.

If you read up on the current dust-up surrounding the admissibility of fingerprints into court under the Daubert standard, you'll understand why knowing what a match means is so important.