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Eyes (and Minds) Deceive: Witness Unreliability Casts Doubt on Death Penalty Rulings

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Three members of the U.S. House of Representatives contacted the Georgia State Parole Board two days ago in a futile attempt to reopen a clemency hearing for Troy Davis, who was executed on the night of September 21 for the killing of a Georgia policeman. In their letter, they pointed out that the board had concluded its hearing without having a chance to hear Jennifer Dysart, a psychologist from the John Jay College of Criminal Justice in New York who is an expert on eyewitness testimony.

The ethics of retaining the death penalty is a decision made by state governments and the courts, but scientists like Dysart have ever more to say about the accuracy of those who witness the crimes that produce death sentences. Parole boards should listen carefully before making up their minds because of the apparent unreliability of these accounts.

The Innocence Project, a litigation and public policy organization affiliated with the Benjamin N. Cardozo School of Law at Yeshiva University in New York, has found that mis-identification by eyewitnesses played a role in three quarters of the 273 cases of mistaken conviction later exonerated by DNA evidence in the U.S. In the Davis case, several of the eyewitnesses recanted their testimony prior to his execution.


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Social scientists, too, have critiqued the validity of procedures used in identifying suspects. On September 19, the same day that the parole board held its clemency hearing, a study by Dysart and colleagues found that witnesses make more accurate identification of suspects in a double-blind, sequential lineup—one in which each individual member is viewed separately and the law enforcement official does not know who the suspect is. Most lineups, including Davis’s, recapitulate the typical Law and Order episode in which all of the members stand side-by-side and the cop knows who the suspect is. In the study, Dysart found that nearly 42 percent of eyewitnesses made errors in the traditional lineup, compared to 31 percent in a sequential one.

In an affidavit prepared for the parole board, Dysart pointed out that after Davis’s arrest in 1989 (see pdf with affidavit, Dysart study and an Innocence Project letter), investigators staged a crime reenactment for eyewitnesses and used “suggestive identification techniques.” In 2008, the Georgia Peace Officer Standards and Training Council adopted an eyewitness identification training program and no longer endorses these practices, which, Dysart contends, contributed to Davis’s misidentification. The psychologist was planning to end her testimony by saying, “…given the significant problems with the eyewitness testimony in this case, there is a substantial danger that multiple witnesses rendered faulty identifications. As a result, the Board should give little weight to the eyewitness testimony introduced by the State.”

It is too late for Davis, but maybe not for others. In June, the New Jersey Supreme Court issued new rules for determining witness reliability before presenting testimony to jurors. And the U.S. Supreme Court has accepted a case that relates to eyewitness identification. Bit by bit, the accumulation of scientific findings may be helping to ensure that the innocent are not wrongfully accused.

 

Source: Wikimedia Commons

 

 

 

 

 

 

 

 

 

 

 

Gary Stix, Scientific American's neuroscience and psychology editor, commissions, edits and reports on emerging advances and technologies that have propelled brain science to the forefront of the biological sciences. Developments chronicled in dozens of cover stories, feature articles and news stories, document groundbreaking neuroimaging techniques that reveal what happens in the brain while you are immersed in thought; the arrival of brain implants that alleviate mood disorders like depression; lab-made brains; psychological resilience; meditation; the intricacies of sleep; the new era for psychedelic drugs and artificial intelligence and growing insights leading to an understanding of our conscious selves. Before taking over the neuroscience beat, Stix, as Scientific American's special projects editor, oversaw the magazine's annual single-topic special issues, conceiving of and producing issues on Einstein, Darwin, climate change, nanotechnology and the nature of time. The issue he edited on time won a National Magazine Award. Besides mind and brain coverage, Stix has edited or written cover stories on Wall Street quants, building the world's tallest building, Olympic training methods, molecular electronics, what makes us human and the things you should and should not eat. Stix started a monthly column, Working Knowledge, that gave the reader a peek at the design and function of common technologies, from polygraph machines to Velcro. It eventually became the magazine's Graphic Science column. He also initiated a column on patents and intellectual property and another on the genesis of the ingenious ideas underlying new technologies in fields like electronics and biotechnology. Stix is the author with his wife, Miriam Lacob, of a technology primer called Who Gives a Gigabyte: A Survival Guide to the Technologically Perplexed (John Wiley & Sons, 1999).

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