Thursday, January 05, 2006

DNA, schmee-en-nay

According to this article in the Washington Post, "Virginia Gov. Mark R. Warner (D) has ordered DNA testing that could prove the guilt or innocence of a man executed in 1992, marking the first time a governor has asked for genetic testing of someone already put to death."

On the one hand, this could be great. People might finally get over the fear that a factually innocent person had been executed. That is a fear than needs to be gotten over because there is nothing wrong with executing the factually innocent. The only "fact" that matters at the execution stage is that (1) a jury has returned a guilty verdict against the individual, pursuant to which (2) a court has entered a criminal judgment against him. (And even (1) is not always necessary; the right can be waived.) With those facts in place, plug in the chair and let 'er rip. It's not that I don't believe claims of factual innocence -- although for the most part I don't -- it's that they simply don't matter.

But I realize that this is NOT the lesson that will be drawn from the investigation, so I feel the need to point out that it will not show what its proponents hope it will show: it cannot conclusively establish that an individual was factually innocent.

Why is DNA evidence considered so sacrosanct? Consider that the attorneys who wave around favorable DNA results are the same ones who attempt to subject other kinds of forensic evidence to such frequent cross-examination that they wish to get it excluded categorically. Borrowing a page from their playbook, there are several reasons -- including some good reasons -- to doubt the results of DNA testing.

First, it can reach results that contradict the results of other kinds of forensic testing. This is not the strongest argument, because it is possible that DNA results are somehow better than fingerprints, blood typing, handwriting analysis, ballistics, etc. Perhaps. But consider two other reasons to doubt the results of DNA analysis: faulty lab procedures (in which I include the outside-the-lab process of collecting samples) and willfully rigged tests.

Consider #2, faulty lab procedures. All forensic analysis is performed by individuals in labs -- the results are the result of potentially flawed execution. Just as forensic evidence can be contaminated in such a way as to indicate that a factually innocent person was guilty, so too is can be contaminated in such a way as to indicate that a factually guilty person is innocent.

And consider #3, the rigged-result. According to defense attorneys (when it suits them) police labs are inhabited by people who are wiling to perform a test often enough until it produces the "right" result. But just as results can be rigged by scientists to produce "guilty" results, so they can be rigged by scientists to produce "factually innocent" results.


<< Home

This page is powered by Blogger. Isn't yours?