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
A disappointed jury can be a dangerous thing. Just ask Jodi Hoos. Prosecuting a gang member in Peoria, Ill., for raping a teenager in a local park last year, Hoos told the jury, "You've all seen CSI. Well, this is your CSI moment. We have DNA." Specifically, investigators had matched saliva on the victim's breast to the defendant, who had denied touching her. The jury also had gripping testimony from the victim, an emergency-room nurse, and the responding officers. When the jury came back, however, the verdict was not guilty. Why? Unmoved by the DNA evidence, jurors felt police should have tested "debris" found in the victim to see if it matched soil from the park. "They said they knew from CSI that police could test for that sort of thing," Hoos said. "We had his DNA. We had his denial. It's ridiculous."
Television's diet of forensic fantasy "projects the image that all cases are solvable by highly technical science, and if you offer less than that, it is viewed as reasonable doubt," says Hoos's boss, Peoria State's Attorney Kevin Lyons. "The burden it places on us is overwhelming." Prosecutors have a name for the phenomenon: "the CSI effect."
Some of the "evidence" the CSI shows tout--using a wound to make a mold of a knife, or predicting time of death by looking at the rate at which a piece of metal might rust--is blatant hokum, experts say. But more and more, police and prosecutors are waking up to the need to cater to a jury's heightened expectations. That means more visual cues, with PowerPoint and video presentations, and a new emphasis during testimony on why certain types of evidence haven't been presented. If there are no fingerprints in evidence, more prosecutors are asking investigators to explain why, lest jurors take their absence as cause for doubt.
The same goes for DNA or gunshot residue. Joseph Peterson, acting director of the Department of Criminal Justice at the University of Illinois-Chicago, says DNA is rarely culled from crime scenes and analyzed. Crime scenes today are much like they were in the 1970s, Peterson says, when his studies found that fingerprints and tool marks were the most common types of evidence left at crime scenes. Blood was found only 5 percent of the time, usually at murder scenes.
Like crime scenes, many crime labs also haven't changed that much--at least in one respect. Many are still understaffed, and they often don't receive all of the relevant physical evidence from the crime scene, either because police investigators don't know what they're looking for or because they figure--possibly wrongly--that the case is strong enough without it. A crime lab's bread and butter is testing drugs found at crime scenes, doing toxicology screens, and comparing fingerprints. DNA matches are way down the list, mainly because they're time consuming and expensive. How much time? A Cape Cod trash hauler gave police a DNA sample in March 2004. The lab was backlogged. Last week, after it was finally analyzed, he was arrested for the 2002 murder of fashion writer Crista Worthington.