Guilty or Innocent?

Science says no, but court officers not reassured.

If real-life technology solved crimes as easily as the methods seen on “CSI” and similar TV shows, there’d be a lot more convictions for criminal offenses in the U.S.

“CSI,” which Nielson says consistently draws more than 10 million viewers a week, takes fans to a world where forensic investigators obtain damning evidence with lightning speed, using tools and methods that sometimes aren’t actually available.

Investigators cannot lift fingerprints from blades of grass or obtain conclusive DNA test results in just a few hours, even though both have happened during episodes of “CSI.”

This disconnect between TV drama and reality has led some judges, prosecutors and journalists alike to be concerned about something they call the “CSI effect.” They worry that jurors may have unreasonable expectations about the quantity and quality of evidence available during a trial, and may be voting to  acquit when what they see falls short.

As a felony trial judge in Ann Arbor, Michigan for the last two decades and one of only seven U.S. judges with a Ph.D. in judicial studies, Judge Donald H. Shelton decided to find out if there is truth to this myth. At this year’s American Academies of Forensic Sciences conference in Atlanta, he presented his findings to a jam packed room.

He’s been studying the so-called “CSI” effect for the last five years, searching for clues about what jurors really expect in the courtroom.

What he has found, he said, is surprising.

Prior to being selected to be on a jury, 1200 potential jurors in Wayne County, Detroit were surveyed about their television watching habits, their expectations about evidence they might see  in seven different hypothetical case scenarios, and whether or not they would demand to see scientific evidence before voting to convict in 13 hypothetical case scenarios.

The study found that almost 60 percent of those surveyed expected to see some kind of scientific evidence in every criminal case, more than 40 percent expected DNA evidence to play a part in every criminal case, and more than half expected fingerprints in every criminal case.

Additionally, more than 70 percent of jurors anticipated DNA evidence in a murder case and 88 percent expected this in rape cases.

“These are big expectations that the prosecution will present some kind of scientific evidence,”  said Shelton, one of only a few U.S. judges who also holds a Ph.D. in judicial studies, at the conference earlier this year.

This expectation softens when  jurors hear eyewitness testimony.

“Jurors are more likely to find the defendant guilty than not guilty even without scientific evidence if there is testimony from the victim or other witnesses, except in rape cases,” said Shelton.

“Jurors still believe eyewitness testimony,” he said. Rape, however, is the one crime where eyewitness testimony is least likely to guarantee conviction in the absence of DNA or some other type of forensic evidence. Jurors expect DNA in rape cases.

Real or not, the “CSI” effect is discussed in law school classes and addressed in courtrooms  by both attorneys and judges, according to longtime University of Georgia Law School professor Ron Carlson, who has been studying the issue since 2005.

“The notion is that the prosecutors feel that jurors, unless they see a lot of CSI type testing, they’re not going to convict,” said Carlson.  “They want to see somebody in a white lab coat, maybe even bringing some test tubes into the court room. And if I were trying a big case, that’s probably what I’d give them.”

Some jurors may have those  expectations, but according to  Shelton’s study that can’t be blamed on watching “CSI.”

“There were no significant differences in the propensity or reluctance of jurors to find a defendant guilty based on whether they watched CSI-type programs,” he said.  “CSI is not a significant factor in those expectations or demands from jurors.”

Instead, he said, a broader “tech effect” in popular culture may have whetted appetites for evidence that looks “scientific.”

“Ordinary people know or at least think they know more science than they learned in school,” he said.

Even though Shelton’s study pretty much dispels the notion that “CSI” watchers are letting the guilty go free, “that myth has become reality,” he said.

Carlson said that judges, prosecutors and defense attorneys are taught to give juries special instructions in closing arguments – telling them they can convict a defendant without mountains of  “CSI”-like science.

He said he had commended one federal court judge in Macon, Georgia for the attention he lavishes on the “CSI” effect, and on dialing back jurors’  evidence expectations.

“He feels it’s an important enough factor that he gives the jurors special instructions,” Carlson said. “And I encourage judges to think about doing that.”

Shelton’s study is not powerful enough to sever the link between jurors’ devotion to “CSI” and  their behavior in the jury room.  In Carlson’s view, anecdotes speak louder.

In a recent case in New Jersey, for example, prosecutors had what they thought would be an open and shut case. A woman was assaulted in the presence of two or three eyewitnesses, and crime scene investigators collected – among other things —  a half-eaten cheeseburger from the defendant very close to the scene of the crime.

Because they had so much  eyewitness and circumstantial evidence in the case, prosecutors didn’t request a lab test for DNA on the cheeseburger. But after they voted to acquit the defendant, jurors said they had freed him because DNA from the cheeseburger was not presented as a means of linking him to the scene of the crime.

Similar cases routinely play out across the country, Carlson said.

Whether CSI is to blame when jurors set aside common sense, or whether there is some other cause,  judges and attorneys must work to make sure that jurors have realistic expectations about forensic evidence in the court of law.

Photo: Promotional photo for "CSI: CRIME SCENE INVESTIGATION" episode "Death & the Maiden" by Sonja Flemming/CBS.

Jessica Luton

I'm a graduate student in UGA's Health and Medical Journalism program. Previously, I was a reporter for a small, community newspaper for three years. I write about health and wellness, technology, crime, politics, food and so much more.