Everyone expects the National Academy of Sciences' report on the state of the forensic sciences to mark a watershed in criminal justice, but since the report itself has not been released, the front page preview of the report in the New York Times relied on accounts from various sources that had seen early drafts.
The article presents a succinct example of how despite getting lots of small pieces exactly right you can get the big story completely wrong. The DNA exoneration cases have thrown a harsh light on tragedies in which the analyses of bite marks, hair and fiber evidence, fingerprints and firearm identification have been “handled by poorly trained technicians who then exaggerate the accuracy of their methods in court.”
With disturbing frequency that slovenly process has resulted in the arrest, conviction, and imprisonment of the wrong man.
But what the Times didn't mention is that every time the wrong man goes to prison, the right man escapes as a result, and is free to find more victims. The perverse effect of this omission is to focus the entire conversation on an illusory Manichean conflict between implacable enemies: the Champions of Innocence in the defense bar and the National Academy on one side, and a conviction-obsessed “law enforcement” monolith on the other.
This conflict is potentially no less destructive for being imaginary. The fact is, no one became a prosecutor, joined the police force, or studied forensic science in order to convict the innocent so that the guilty could go free. Most of the people who actually practice in the criminal justice system recognize a shared interest in good forensic science. Where reforms in investigative procedures have been implemented in the wake of the DNA exonerations–for example, in the area of eyewitness lineup practices–it has been because of the cooperative presence on Innocence Commissions or Technical Working Groups of representatives of all of the criminal justice system's practitioners: cops, prosecutors, defenders and scientists.
Productive discussion of the NAS report is threatened by another favorite theme that haunts the Times piece: the hunt for the “bad apple.” Since we know there have been tragic wrongful convictions based on bad science–according to this view–there must have been bad scientists. The trick is to find them. The Times leaves the impression that the hunt for–and discipline of–these bad apples is what the NAS Report is (and should be) all about.
Well, there are bad scientists. But no bad scientist on his or her own was enough to cause a wrongful conviction. It took bad hiring, bad funding, bad training, uninformed prosecutors and defenders, and lax legal criteria, to send the wrong man to prison. A wrongful conviction is an “organizational accident” made up of many active mistakes interacting with existing latent conditions.
Aviation and–increasingly–medicine have grasped this point. As Dr. Lucien Leape put it in his classic essay, Error In Medicine: “While the proximal error leading to an accident is in fact, usually a “human error,” the causes of that error are often well beyond the individual's control. All humans err frequently. Systems that rely on error-free performance are doomed to fail.”
The NAS report will catalogue vivid, horrifying tragedies, but it will also try to confront close and complex questions about the nature of science and of the systems that we rely on to mobilize science in the cause of justice, not a slugging match between good and evil. We ought to read the report before we write about it, and we ought to try and read it with the seriousness the issues deserve.