What about Frye? The Admissibility of IDs from Faulty Police Lineups

It is well-settled among social scientists who have studied the mechanisms of eyewitness memory that certain police practices are likely to enhance the reliability of identifications resulting from police lineups, whereas certain faulty practices have been demonstrated to diminish that reliability. Yet under federal due process law (i.e. Manson v. Brathwaite), identifications from egregiously flawed police lineups are routinely admitted because the result is found to have an independent source, notwithstanding the suggestivity of the lineup procedure.

Courts have widely interpreted Manson -- however wrongly -- to mean that it really doesn't matter how suggestive a procedure is, as long as the witness had, for example, a sufficient opportunity to view the perpetrator such that she would theoretically have been able to ID the person if the police hadn't gone out of their way to suggest that their suspect was the guy. Under that unfortunate interpretation of the governing rule, due process has been rendered a fundamentally ineffective legal vehicle for challenging the admissibility of suggestive and otherwise unreliable police lineups.

But what about Frye? Here in DC, in order to introduce evidence that flows from a scientific procedure, the proponent of the evidence must show that "the thing from which the deduction is made [is] sufficiently established to have gained general acceptance in the particular field in which it belongs." A police lineup is a scientific experiment designed to test an eyewitness's ability to accurately recall the identity of the perpetrator. The community of experts in the field of human memory are in a state of broad consensus with respect to the lineup procedures that make for a reliable test of human memory, and those that make for a poor one. When there is anything short of a consensus among that community -- that is, the community of social scientists who have actually researched the effectiveness of the procedures employed by police to test witness memory -- with respect to the reliability of a particular procedure, identifications flowing from those unreliable procedures should be excluded from use in criminal trials.

The question before the court in Frye itself was similar, when it was faced with a challenge to the admissibility of the results of a polygraph test. The polygraph is designed to test the accuracy of a person's account of some event. A police lineup is also designed to test the accuracy of a person's account of some event, and specifically, the identity of the perpetrator. When a lineup is administered in accordance with settled best practices -- i.e. with proper instructions, conducted by someone who does not know the identity of the suspect, with an adequate number of fillers, where the fillers match the characteristics of the original description, with only one suspect per lineup, etc. -- then the relevant community of scientists are in consensus that the procedure is more likely to yield an accurate identification. When those procedures are not followed, there is broad consensus for the exact opposite proposition -- namely, that the procedure and any identification that flows from it are demonstrably unreliable.

Evidence flowing from an unreliable test of memory should be excluded for the same reasons that the DC Court of Appeals excluded evidence from the polygraph test in 1923: its proponents cannot establish that it reliably produced the evidence it was purported to produce.

So why not use Frye (and, equally, Daubert) to keep out unreliable IDs? It just struck me that you shouldn't even need due process to keep out the results of a procedure whose unreliability is corroborated by a broad consensus among scientists.

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LeGrand reversed! (NY Murder Conviction Overturned for Denial of ID Expert)

As previously reported, last month the New York Court of Appeals heard oral arguments in People v. LeGrand, a murder case in which the trial judge last year refused to admit expert testimony (PDF) on the reliability of eyewitness identifications, and further held that such evidence is unreliable under the "general acceptance" standard set forth in Frye v. United States.

Today, New York's high court reversed (PDF) the conviction, on grounds that it was an abuse of discretion for the trial court to exclude expert testimony on the reliability of of eyewitness identifications. With respect to the lack of correlation between confidence and accuracy and "the effect of postevent information on accuracy and confidence malleability," it is error to exclude expert testimony in a case in which the identification is central and there is a lack of corroborating evidence.

In short, the law on expert testimony on eyewitness ID in New York now appears to be:

It is an abuse of discretion to exclude an ID expert when:
- The case turns on an uncorroborated eyewitness ID; and
- The subject matter of the expert's testimony is generally accepted by experts in the field and beyond the ken of the average juror.

And the following factors affecting eyewitness reliability are both generally accepted and beyond the ken:
- Lack of correlation between confidence and accuracy;
- The adverse effect of confirming feedback on eyewitness accuracy; and
- The malleability of eyewitness confidence.

On the above topics, the court at least implied that Frye hearings would no longer be necessary to establish general acceptance prior to admission of expert testimony. The court did not find the "weapon focus effect," however, to be generally accepted among the relevant scientific community, despite substantial research on the subject.

As previously reported, the case was expertly briefed by the Center for Appellate Litigation in New York, with amicus support (PDF) from the Legal Aid Society, Neighborhood Defenders of Harlem, and the New York State Criminal Defense Lawyers Association.

[Cross-posted at Daily Kos.]

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Eyewitness ID Research: Generally Accepted Science? (People v. LeGrande, NY Court of Appeals)

On Wednesday, the New York Court of Appeals heard oral arguments in People v. LeGrand, a case in which the trial judge last year refused to admit expert testimony (PDF) on the reliability of eyewitness identifications, and further held that such evidence is unreliable under the "general acceptance" standard set forth in Frye v. United States.

The case stems from a murder that occurred in upper Manhattan in 1991, and the first lead on a potential culprit emerged a full seven years later, when investigating officers showed a photo array including Mr. LeGrand to witnesses. Based on a seven year old memory of the events, one witness claimed that Mr. LeGrand was the killer; other witnesses admitted that they saw "similarities," but stopped short of making a positive ID -- and others could not make an ID at all. The first trial resulted in a hung jury, but the second ended with a conviction and a 25-year-to-life sentence for Mr. LeGrand.

On appeal, the core issue is whether or not the trial court should have admitted expert testimony on the reliability of eyewitness identifications, particularly in a case where the only ID occurred seven years after the incident, there was a weapon involved, and other issues tending to reduce the reliability of eyewitness identifications were central to the sole evidence purporting to connect Mr. LeGrand to the murder.

During oral arguments yesterday, at issue was Saul Kassin's survey on the "general acceptance" of various issues relating to eyewitness evidence, including the "weapon focus effect" -- an important issue in this case (in addition to confidence-accuracy correlation, the effect of post-event information on eyewitness memory, and confidence malleability). Kassin's survey revealed that 87% of experts polled found the "weapon focus effect" to be reliable and supported by the scientific research, yet the trial court judge refused to allow testimony on the subject, and further found that it is neither reliable nor generally accepted in the relevant scientific community.

This case was expertly briefed by the Center for Appellate Litigation in New York, with amicus support from the Legal Aid Society, Neighborhood Defenders of Harlem, and the New York State Criminal Defense Lawyers Association. Definitely a case to watch, and thanks to Kate for the heads up.

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