The Passions and the Interests in Forensic Science

by Roger Koppl

A front-page article  in yesterday’s Washington Post underlines the importance of establishing a substantive defense right to expertise in the US.

The article says, “Justice Department officials have known for years that flawed forensic work might have led to the convictions of potentially innocent people, but prosecutors failed to notify defendants or their attorneys even in many cases they knew were troubled.” The DoJ begin investigating in the 1990s “after reports that sloppy work by examiners at the FBI lab was producing unreliable forensic evidence in court trials.” As the Post article chronicles, the investigation was very narrowly drawn in spite of evidence that problems were likely more widespread. When problems were identified, the FBI gave notice to the relevant prosecutors, but not to defendants or their legal representatives. To judge by the sample the Post was able to track down, prosecutors notified defendants in only about half the cases. This is not the first case of slow or inadequate notification.

Oversight is a common prescription from those who recognize problems with the system. I have expressed my preference for a different approach, one that chooses checks and balances over hierarchy. The Post article points to a big problem with oversight. It quotes University of Virginia School of Law professor Brandon L. Garrett saying, “You can have cautious standards, but if no one is supervising their implementation, it’s predictable that analysts may cross the line.” Garrett favors oversight, and he seems to be calling for more of it in the quote.

But it is cumbersome to have an oversight body monitoring forensic science testimony. How will the standards set be enforced? Presumably, they would not attempt to monitor each individual act of forensic-science testimony. But how then, will an oversight body ensure that each bit of testimony is consistent with the principles of science? Who will “supervise” the “implementation” of “cautious standards”? And, ahem, who will monitor the monitors? In an earlier post have expressed concern over the regulatory capture of forensic science.

If I may repeat what I have said elsewhere, a defense right to forensic expertise is the single best way to reduce the incidence of false and misleading forensic science testimony.  E. James Cowan and I explain  why competition between “strongly opposed” experts tends to improve the quality of information they provide to third parties such as juries. “If the interests of the competing information suppliers are strongly opposed then one of them always has an incentive to provide additional information.”

If some bit of relevant information has not been revealed, then, by virtue of the fact that it is relevant, it will help one side or the other. Accordingly, one side or the other will have an incentive to reveal it. This logic works even if both sides are biased. It requires only that their interests in the case be strongly opposed. (This argument is pure Milgrom and Roberts.) Thus, the adversarial system of Anglo-American jurisprudence allows for pitting one bias against another to produce results that more closely resemble the consequences of unbiased analysis. Although it is important to attempt to reduce bias by measures such as sequential unmasking, all such measures are incomplete. The remaining biases should also be leveraged by pitting one expert against the other. We need checks and balances.

The existence of defense experts in forensic science would also create a self-renewing foundation for continuous improvement in forensic science. Many reforms do not stick. A new reform is generally effective only when it is first applied, and perhaps not even then.

If the reform works initially, it is because the affected parties have no coping strategies. Over time, however, those affected parties learn compensating strategies and the reform loses its beneficial effects. The reform does not stick. For example, affected parties may capture an oversight body. A body of scientific experts similar to public defenders and allied with them would, however, act to preserve its own existence in much the way that public defenders are unlikely to be subverted from their adversarial role.

The reform creating such a group is, therefore, a self-sticking reform. The reform creates an organized body of persons with a direct interest in maintaining the reform. Once this reform is in place, each criminal case will have two forensic experts with strongly opposed interests. Each side will have an incentive to document the upstream deficiencies of the system and bring them to the attention of the court whenever that is strategically appropriate. In this way, competing forensic experts become the central self-regulatory element of the system. Such a reform would be truly transformative of the criminal justice system in America.

8 thoughts on “The Passions and the Interests in Forensic Science

  1. I just watched Frontline’s “The Real CSI.” I must admit to some mixed feelings. The diagnosis of problems with forensic science was pretty good. There are more “false positive” errors than most folks imagine. It was great to see more attention given to the problem. But the show was all about the creating national standards and some sort of national oversight body. NAS report featured in the show (which cites the “sequential unmasking” letter I helped draft) proposes such a body calling it the National Institute for Forensic Science (NIFS). The risk of regulatory capture is quite high in this case, and one large and well-organized interest at issue is law enforcement. Indeed, the leading reform measure in Congress now would put a NIFS-like agency under the Department of Justice. ( It looks like Congress will give us either nothing or a law enforcement controlled NIFS, with all its pernicious effects. I’m afraid such a NIFS would likely do more harm than good. I’ve discussed regulatory capture of NIFS in links given above, namely here:
    and here:

  2. How about the separation of law and State? Also, abolish the FBI, which is as good at doing investigations as the Fed entity is at monopolizing the money supply and preventing business cycles and unemployment.

  3. There seems to be a kind of good and bad side of everything. Some suggests to get rid of the FBI and that’s honestly not going to resolve anything. I’m not advocating for forensic teams but lets be serious, EVERYONE makes mistakes. Sure there are thousands of cases where the wrong person has been convicted but the truth is nobody is perfect and mistakes are sure to happen in this filed of work. However, what i do support are regulations. Any forensic team should require major analysis, not only for their own department but from others as well. The more you have someone watching over you the less or mistakes you can cause.

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