gas chromatograph, which is a real instrument, but it was shown in an unlikely location: an investigator's van. "They cost about $60,000 to $80,000, and nobody in their right mind would ever mount one in a car. Because the first time you go over a pothole, you'd have to recalibrate the entire machine," he said, "but it is a real machine, and it's used for detecting drugs."
In the scene, an investigator tests for the presence of a drug by swabbing a sink at the crime scene with a probe, which looks like an elongated Q-tip. The probe turns bright blue, suggesting a positive test. "It's television, so it always has to be a glowing blue," Marquis said. "It's really a black sludge."
The material on the probe is then examined by the gas chromatograph, which produces a results chart within seconds. "It is, in fact, what would be generated in about two and a half weeks when you send it in for analysis," Marquis said. "So in that case, they weren't making stuff up; there are really gas chromatographs. But the process was so easy and so fast that I think it creates false expectations."
Shades of Gray
Real-life crime lab equipment is big, bulky and not photogenic, according to Krane. "The equipment you see in CSI tends to be handheld and you get to focus more on the actor than the equipment." And unlike television gadgetry, the results produced by real tools often are ambiguous.
"In CSI, they have these sorts of magic lights they can shine on crime scenes that illustrate to them where the best evidence samples are," Krane said. "Black light really does help illuminate things you wouldn't see otherwise, but everything is simpler, easier and less complicated [on TV] - relative to what it is in the real world."
In real-life investigations, 50 percent to 75 percent of forensic evidence samples taken from crime scenes are difficult to interpret, according to Krane, due to degradation, contamination and small sample sizes. That leaves far more room for subjective analysis.
"The reality is," Marquis said, "that real crime is very messy, and in real life, it isn't as crisp as it is on TV. It raises unrealistic expectations about technology that really does exist and in a perfect world we would be able to do it."
Does It Matter?
What's the practical impact of the CSI Effect? Legal practitioners disagree.
Defense attorney and DNA expert Robert Blasier downplays the danger. "I think the CSI Effect is grossly overrated," said Blasier, who worked for the defense on both the Phil Spector and O.J. Simpson trials. "Both sides in a case usually talk about the fact that it's not anywhere near close to real life. You always bring it up.
"I just don't think the jurors really confuse television with reality," he continued. "If there's a particular forensic test and you think a jury might have some unreal expectations, I always will bring it up in cross examination: 'You understand that this is not television and you can't get a DNA result over a 30-second commercial. It just doesn't work that way, and the DNA technology is still relatively primitive.'"
Barry Fisher, crime lab director of the Los Angeles County Sheriff's Department, called the CSI Effect "media spin," but he admitted it can alter cases. "One of the things that might happen is we're asked to do more tests than we might be asked to do otherwise," he said. "One of the things district attorneys often argue is, we have to do these tests in anticipation of them being raised [as questions] by the defense."
Marquis said he put crime technicians on the witness stand for