Do TV Shows Like CSI Really Influence Juries?

The March 2008 issue of the Journal of the National Institute of Justice in the United States features an article entitled The 'CSI Effect': Does It Really Exist?

The article describes an empirical study that tried to see what impact popular shows about police investigations such as CSI: Crime Scene Investigation may have been having on the expectations and behaviour of jury members in criminal cases.

It is well worth the read.

There has been an assumption that shows like CSI had been causing jurors to wrongfully acquit objectively guilty defendants when no fancy, flashy TV-style forensic evidence was presented at trial.

The article summarizes the findings of a survey of just over 1,000 randomly selected jurors in a Michigan city in the summer of 2006. They were asked what kind of evidence they expected to see in different cases, and whether they would demand to see scientific evidence before they would find a defendant guilty.

The findings showed that CSI-type shows do not appear to have spoiled juries:

"Interestingly, in most of the scenarios presented, potential jurors' increased expectations of scientific evidence did not translate into a demand for this type of evidence as a prerequisite for finding someone guilty. Based on our findings, jurors were more likely to find a defendant guilty than not guilty even without scientific evidence if the victim or other witnesses testified, except in the case of rape. On the other hand, if the prosecutor relied on circumstantial evidence, the prospective jurors said they would demand some kind of scientific evidence before they would return a guilty verdict."

"There was scant evidence in our survey results that CSI viewers were either more or less likely to acquit defendants without scientific evidence. Only 4 of 13 scenarios showed somewhat significant differences between viewers and non-viewers on this issue, and they were inconsistent."

(...)

"Although CSI viewers had higher expectations for scientific evidence than non-CSI viewers, these expectations had little, if any, bearing on the respondents' propensity to convict. This, we believe, is an important finding and seemingly very good news for our Nation's criminal justice system: that is, differences in expectations about evidence did not translate into important differences in the willingness to convict."