The CSI Effect
On TV, it's all slam-dunk evidence and quick convictions. Now juries expect the same thing--and that's a big problem
Other forensic tests are even more open to interpretation. Everything from fingerprint identification to fiber analysis is now coming under fire. And rightly so. The science is inexact, the experts are of no uniform opinion, and defense lawyers are increasingly skeptical. Fingerprint examiners, for instance, still peer through magnifying glasses to read faint ridges.
Many of these techniques and theories have never been empirically tested to ensure they are valid. During much of the past decade, coroners have certified the deaths of children who might have fallen down steps or been accidentally dropped as "shaken baby" homicides because of the presence of retinal hemorrhages--blood spots--in their eyes. Juries bought it. Noting that new research casts grave doubt on the theory, Joseph Davis, the retired director of Florida's Miami-Dade County Medical Examiner's Office and one of the nation's leading forensics experts, compares proponents of shaken-baby syndrome to "flat Earthers" and says its use as a prosecution tool conjures up "shades of Salem witchcraft" trials.
The list goes on. Ear prints, left behind when a suspect presses his ear to a window, have been allowed as evidence in court, despite the fact that there have been no studies to verify that all ears are different or to certify the way ear prints are taken. The fingerprint match, once considered unimpeachable evidence, is only now being closely scrutinized. The National Institute of Justice offered grants to kick-start the process this year. Other "experts" have pushed lip-print analysis, bite-mark analysis, and handwriting analysis with degrees of certainty that just don't exist, critics say.
Microscopic hair analysis was a staple of prosecutions until just a few years ago and was accorded an unhealthy degree of certitude. "Hair comparisons have been discredited almost uniformly in court," says Peterson of the University of Illinois-Chicago. "There are many instances where science has not come up to the legal needs," adds James Starrs, professor of forensic sciences and law at George Washington University. Everyone, including the jury, wants certainty. But it seldom exists in forensics. So the expert, says Starrs, "always needs to leave the possibility of error."
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Details on forensics, the law, and how they intersect are available in a free database at the National Clearinghouse for Science, Technology, and the Law, a program of the National Institute of Justice, at ncstl.org/
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