Wednesday, April 18, 2007

Faulty Forensics

Friend and co-author Roger Koppl has an excellent op-ed in the New York Post, using the Duke rape case as a jumping point to discuss the larger problem of biased forensics. Here's a sampler, but read the whole thing:
DNA is no magic bullet of truth when the testers are aligned unambiguously with the prosecution. During the testimony in which it was revealed that Nifong and Meehan had agreed to hide the DNA evidence, Meehan referred to Nifong as "my client." Instead of serving the truth, Meehan's forensics lab was helping its "client," the prosecutor.

When forensic scientists work exclusively for the prosecution, we should expect errors and abuse. Using post-conviction DNA evidence, the Innocence Project has helped exonerate nearly 200 people wrongly convicted of crimes. A study of the first 86 such cases, published in the journal Science, found faulty forensics played a role in almost two-thirds of those convictions.
The basic problem here is that forensic labs are hired almost exclusively by the prosecution, while the defense has little access to the materials necessary to conduct their own forensic tests. He who pays the piper calls the tune, as they say, so biased forensic results and testimony should come as no surprise.


abs said...

I'm not really sure it follows that, "[w]hen forensic scientists work exclusively for the prosecution, we should expect errors and abuse."

I think that when ANYBODY conducts such investigations we must expect errors, but abuse is a totally different question. Obviously, the adversarial legal system has its disadvantages in the sense that supposed 'experts' will testify to the facts from one point of view, but that's why we have cross examination.

The problem is that no matter how impartial we make the labs that conduct these investigations, the people will always be swayable to one side or another. If the investigators are already inclined to conspire with one side, it's just a matter of economics.

I'm in total favor of allowing the defense to conduct their own tests using their own experts which may or may not come to different conclusions. One way to do that may be to force the government, if they want to introduce DNA evidence, to pay for defense's lab fees at a lab of their choosing.

Glen Whitman said...

Abs -- if you think that "the [lab] people will always be swayable to one side or another," then I think we're agreeing. All I'm saying is that it's totally predictable which direction they will be swayed, given who's giving them their business.

abs said...

But Glen, the forensic field tries to be neutral with technicians adhering to ethical rules and standards similar to the attorneys that they serve. The fact here is that only the analysts who are already corrupt will be swayed by the economic incentives. The assumption you seem to be making is that by virtue of working for the prosecution, the analysts are presupposed to be on the prosecution's side, and on that I disagree.

Glen Whitman said...

If only ethical standards and guidelines were as effective as actual economic incentives. I think you underestimate the amount of room for subjectivity there is in forensic testing. There's not always a simple yes/no answer or a simple number to report. Forensic technicians have to use their judgment to decide how "close" a match is. I think this is a place where the TV crime dramas get it right; watch an episode of Law & Order to see how the prosecutors negotiate with the forensic technicians about how they will characterize their findings. And whether they get continued business will depend in part on how often they are willing to corroborate the prosecution's theory. While some technicians may already be corrupt, and others incorruptible, I think the real issue is those on the margin who can be influenced to slide along the scale.