Tuesday, June 26, 2007

Federal Court Gets ID Science Terribly Wrong, Denies Expert Testimony

In one of the worst eyewitness ID decisions I've read, the US District Court for the Eastern District of Virginia denied expert testimony in US v. White earlier this month, and in the process revealed a substantially flawed comprehension of eyewitness research. US v. White, Slip Copy, 2007 WL 1768718 (E.D.Va. June 15, 2007).

The case involves a police officer as a witness, and despite a wealth of research demonstrating that cops are no better at remembering faces than anyone else -- even when specifically "trained" to do so -- the court relied substantially on that fact in distinguishing this case from other cases in which expert testimony on eyewitness issues had been admitted previously:

First, unlike Lester and other cases admitting expert testimony on eyewitness identification, the eyewitness in the instant case is a trained police officer. Officer Catterton served as a military police officer for the United States Army for six years. He has been trained to be constantly observant of his surroundings, especially the people he encounters on the job. He has been specifically trained to observe and remember the faces he comes across so that they may be later identified. This is in sharp contrast to the participants in Dr. Cutler's cited studies, the majority of whom were college students.

In fact, the specific question of cops vs. college students as eyewitnesses has been studies, and all the evidence shows that trained police are no better at remembering perpetrator identities than random college students. See, for example, a 1998 study by Christianson & Karlsson: Police personnel as witnesses to a violent crime, 3 L. & Crim. Psychol. 59 (1998) (cops are no better at identifying perpetrators than civilian college students). And yet judges continue to rely on this false notion in rendering critical decisions, and in turn juries end up relying on the same false notion in their deliberations, because actual experts are prohibited from testifying to the actual scientific findings that clearly clash with the widely held common sense view.

The police-are-better-witnesses misconception was only the first of the court's errors in rendering this decision.

Confidence and Accuracy

The court also misinterpreted the research on the relationship between the confidence of an eyewitness, and that witness's accuracy. The court characterized the research as showing that "an extremely confident eyewitness is more likely to be accurate than a less confident eyewitness, but only by a modest amount." In fact, the research shows that there is a modest correlation between confidence and accuracy only under very narrow circumstances, more resembling a vacuum than the real world, which rarely occur in actual practice -- namely, if the confidence of a witness is recorded immediately following the identification procedure, and only when no other factors are present to corrupt the witness's perception, such as routine suggestive police practices. In most real-world contexts, there is no correlation between confidence and accuracy, and in some cases even a negative correlation has been observed.

This case was no vacuum. By the time the officer made the identification in this case, he had already been exposed to the strong suggestion of Mr. White's guilt -- he was told that Mr. White had been arrested previously on a similar charge, was suspected of the current charge, and on those grounds the officer requested that his arrest photo be sent over. By the time the officer-witness encountered Mr. White in person, there was little doubt that he would make an identification, regardless of whether or not Mr. White was the actual culprit. There is little question that expert testimony on the lack of correlation between confidence and accuracy would have helped dispel a common misconception in the minds of jurors, and thus enhancing the accuracy of their deliberations.

Cross-Racial IDs, Mugshot Exposure, and Show-Ups

The court went on to deny expert testimony on the cross-race impairment, namely that members of one race are more likely to mis-identify members of another race, despite the fact that the phenomenon is well-documented in the scientific literature and has been shown to be misunderstood by juries.

The court made similar errors with respect to the mugshot commitment effect, and the suggestivity of show-up procedures.

As the exonerations continue to show, juries are going to keep getting it wrong until judges allow science into the courtroom to undo the widely held errors of common sense on the reliability of eyewitness evidence. In the meantime, at least there's Tennessee.

No comments: