Tennessee High Court Overturns Death Penalty Conviction For Failure to Admit ID Expert

I'm on the road so this is brief and nearly old news by now, but with that out of the way:

This great opinion (PDF) came down from the Tennessee Supreme Court this week in State v. Copeland, overturning its long-standing precedent excluding eyewitness testimony as common sense, citing (among other things) a poll (PDF) conducted by the Public Defender Service for DC, showing that jurors tend to overestimate the reliability of cross-racial IDs. The defendant in the case had been sentenced to death, but the Tennessee Supreme Court overturned the conviction for the trial court's failure to admit the expert testimony of Jack Brigham on the cross-race effect.

One point that was raised that never receives enough attention is the disparity in admissibility requirements for government vs. defense expert witnesses. So-called "narcotics experts" (i.e., cops) are routinely allowed to testify as experts on the subtleties of drug transactions, and yet eyewitness ID experts (i.e, PhD psychologists) are routinely precluded from testifying:

Another author has observed that while experts are often not permitted to testify regarding eyewitness testimony, police officers and other law enforcement officials are regularly permitted to testify “concerning the general way criminal
schemes and enterprises operate and the usual meaning of criminal slang and code words.” D. Michael Risinger, Navigating Expert Reliability: Are Criminal Standards of Certainty Being Left on the Dock?, 64 Alb. L. Rev. 99, 132 (2000). The author contrasts the “technical” knowledge of the law enforcement officials with the educational and scientific credentials of experts on eyewitness identification. Id. at 131-35.

It is the educational training of the experts and empirical science behind the reliability of eyewitness testimony that persuades us to depart from the Coley rule. Times have changed. Today, many scholarly articles detail the extensive amount of behavioral science research in this area. See generally Gary L. Wells et al., Eyewitness Evidence: Improving Its Probative Value, 7 Psychol. Sci. Pub. Int. 45, 47-49 (2006) (for a brief history of psychological research of eyewitness testimony).
There are literally hundreds of articles in scholarly, legal, and scientific journals on the subject of eyewitness testimony.

And on how cross-examination is rarely enough to undermine faulty eyewitness testimony in the minds of the jury:

Further, the research also indicates that neither cross-examination nor jury instructions on the issue are sufficient to educate the jury on the problems with eyewitness identification, contrary to the conclusion reached by the majority in Coley. See, e.g., id. (“[E]ven when presented with an eyewitness who was quite thoroughly discredited by counsel, a full 68% still voted to convict.”) (citing Elizabeth Loftus, Reconstructing Memory: The Incredible Eyewitness, 15 Jurimetrics J. 188, 189-90 (1975)). “Considered as a whole, the studies of juror knowledge and decision making indicate that expert psychological testimony can serve as a safeguard against mistaken identification.” Steven D. Penrod & Brian L. Cutler, Preventing Mistaken Identification in Eyewitness Identification Trials, Psychology & Law: The State of the Discipline 89, 114 (1999).

More in the opinion (PDF), which is well worth a read.