Forensic Evidence and the CSI Effect

The media’s popularization of certain types of evidence may be inspiring a “CSI effect” on decision makers. See CSI Effect (Wikipedia). Any finder of fact must rely on their experiences and common sense in evaluating evidence, but not expert knowledge that they have acquired or believe they possess. There is a question about whether impressions created by the media in its treatment and portrayal of forensic proof as either irrefutable or absolutely necessary for conviction is truly impacting the outcome of criminal cases.

A growing body of research is examining this “CSI effect” from the defense and prosecution perspectives. See, e.g., The CSI Effect, The Economist, April 22, 2010. For example, juries might be overly impressed with and uncritical of fingerprint or DNA test results or contrarily have unrealistic expectations about the need for such evidence or its accuracy and reliability.

In a sense the media version of forensic science and criminal procedure may serve as a thirteenth juror, informing the lay person’s expectations and beliefs about the efficacy of particular forms of evidence and the conduct of trials. See The CSI Effect: How TV Influences True Crime, Discovery, April 28, 2010. In either case, the fair administration of justice may be affected by these perceptions of forensic testing. See, e.g., Call for Forensics Overhaul Linked to ‘CSI’ Effect, NPR, Feb. 19, 2009; see generally Strengthening Forensic Science: The Next Wave of Scholarship, LLRX, Nov. 23, 2009.

This is a collection of select legal scholarship and media studies that illuminates the extent of the phenomenon and whether it needs to be addressed and how. It should be noted that there is a large body of news articles, short-form scholarship, books and other media concerning this topic that is not covered in this survey. See generally Bibliography of Resources Related to the CSI Effect (NCSTL 2008); Getting a Grip on the CSI Effect: The National Clearinghouse for Science, Technology and the Law at Stetson University, LLRX, May 15, 2005.


Before the Verdict and Beyond the Verdict: The CSI Infection Within Modern Criminal Jury Trials, 41 Loy. U. Chi. L.J. 119 (2009)
“In criminal law, the term ‘CSI Effect’ commonly refers to the perceived impact the CSI television show has on juror expectation and unexpected jury verdicts. This article coins a new phrase, ‘CSI Infection,’ by focusing on the significant legal impact that the fear of ‘CSI Infected Jurors’ has made upon the criminal justice system. The CSI Infection is the ubiquitous ‘It’ factor that scholars cannot conclusively prove nor effectively explain away; however, practitioners overwhelmingly confirm the CSI Effect’s impact on criminal jury trials. The CSI Effect’s existence, the CSI Effect’s true or perceived impact on acquittals and convictions, and how to define the CSI Effect, permeates criminal trials. For example, litigators base their motions on the CSI Effect and build their trial strategies around the CSI Effect, transforming the legal arguments of trial lawyers on both sides of a case. Specifically, voir dire questions, jury instructions, as well as opening statements and closing arguments have been modified and correspondingly challenged on appeal – all because of the CSI Effect.

Moreover, the phenomenon has forced trial courts to address the evidentiary, procedural, and constitutional issues raised by prosecutors and defense attorneys who fear the perceived dangers that CSI Infected Jurors have upon the ultimate fairness of the jury trial process. Because of the controversy concerning the CSI Effect, judges now issue rulings directed at the perceived impact of the CSI Effect within cases and give special jury instructions regarding the potential role the CSI Effect plays in jurors’ decision making. This CSI Infection, undoubtedly, is creating a juridical migraine for trial courts about issues that were previously ordinary, yet have become increasingly thorny and multifarious considerations of procedure and constitutionality. There is no panacea to either eradicate the fears of the CSI Effect or completely alleviate its influence. Notwithstanding the CSI Effect’s presence or absence, mandatory due process requirements remain. This Article explores the cases, the experiences of litigators, the commentary of jurors, and most significantly, the trial and appellate court rulings on important constitutional and procedural issues. Scrutinizing these legal questions both ‘before the verdict’ and ‘beyond the verdict’ are essential to ensure that justice and fairness prevail over any improper prejudice or bias that may have infiltrated the American criminal justice system.”

Crime Scene Investigation (As Seen On TV), Forensic Sci. Int. (March 12, 2010)
“A mysterious green ooze is injected into a brightly illuminated and humming machine; 10s later, a printout containing a complete biography of the substance is at the fingertips of an attractive young investigator who exclaims ‘we found it!’ We have all seen this event occur countless times on any and all of the three CSI dramas, Cold Cases, Crossing Jordan, and many more. With this new style of ‘infotainment’ (Surette, 2007), comes an increasingly blurred line between the hard facts of reality and the soft, quick solutions of entertainment. With these advances in technology, how can crime rates be anything but plummeting as would-be criminals cringe at the idea of leaving the smallest speck of themselves at a crime scene? Surely there are very few serious crimes that go unpunished in today’s world of high-tech, fast-paced gadgetry. Science and technology have come a great distance since Sir Arthur Conan Doyle first described the first famous forensic scientist (Sherlock Holmes), but still have light-years to go. ”

The “CSI Effect”: Better Jurors Through Television And Science?, 24 Buff. Pub. Interest L.J. 211 (2005)
“This Comment explores how television shows such as CSI and Law & Order have created heightened juror expectations in courtrooms across America. Surprise acquittals often have prosecutors scratching their heads as jurors hold them to this new ‘Hollywood’ standard. The Comment also analyzes the CSI phenomena by reflecting on past legal television shows that have influenced the public’s perception of the legal profession and how the ‘CSI effect’ has placed an even greater burden on parties to proffer some kind of forensic evidence at trial. ”

The “CSI Effect”: Does It Really Exist?, NIJ Journal No. 259, March 2008
“To date, the limited evidence that we have had on this issue has been largely anecdotal, based primarily on prosecutor interviews with jurors after trials. Now, however, we have some findings based on a formal study that two researchers and I recently performed.

Gregg Barak, Ph.D., and Young Kim, Ph.D., criminology professors at Eastern Michigan University, and I surveyed 1,000 jurors prior to their participation in trial processes. The prospective jurors were questioned regarding their expectations and demands for scientific evidence and their television-watching habits, including CSI and similar programs. Our goal was to determine if there was any empirical evidence behind the commonly held beliefs that juror expectations for forensic evidence—and their demand for it as a condition for conviction—are linked to watching law-related television shows.”

The “CSI Effect”: Exposing the Media Myth, 16 Fordham Intell. Prop. Media & Ent. L.J. 429 (2006)
“[T]his study attempts to amass the first empirical evidence of whether a ‘CSI Effect’ exists, what it is, and whether it impacts the administration of criminal justice via juror deliberations. To that end, after detailing three conceptions of ‘The CSI Effect,’ this paper advances a theory of media influence on lay understandings of law. It then extends that base to articulate the operation of a so-called ‘CSI Effect.’ Next, the paper turns to empirical investigation, presenting a study of 254 jury eligible adults who responded to surveys of television and CSI viewing habits as well as to a criminal law scenario measuring the potential impact of CSI viewing. The results show that, despite numerous media stories and law enforcement warnings of a ‘CSI Effect’ crippling our criminal justice system, no such effect exists – at least not any effect that harms, rather than helps, the prosecution.”

The CSI Effect: Fact or Fiction, 115 Yale L.J. Pocket Part 70 (2006)
“As chief prosecutor for Maricopa County, which includes the city of Phoenix, my office prosecutes about 40,000 felonies each year and includes a staff of 300 prosecutors. In June 2005, we surveyed 102 of those attorneys, all of whom had trial experience, and they reported that the CSI effect is no myth: Of the prosecutors we surveyed, 38% believed they had at least one trial that resulted in either an acquittal or hung jury because forensic evidence was not available, even though prosecutors believed the existing testimony was sufficient by itself to sustain a conviction. In about 40% of these prosecutors’ cases, jurors have asked questions about evidence like ‘mitochondrial DNA,’ ‘latent prints,’ ‘trace evidence,’ or ‘ballistics’—even when these terms were not used at trial.”

The “CSI Effect” and Other Forensic Fictions, 27 Loy. L.A. Ent. L. Rev. 87 (2006/2007)
“Guided by media theory, this Article analyzes claims of the CSI Effect from both theoretical and empirical perspectives. After describing the operation of the CSI Effect and its alleged impact, this Article summarizes the effects-based literature explaining the entertainment media’s contribution to the public’s understanding of the law. Applying this body of research, this Article subjects claims of a CSI Effect to a set of empirical investigations. The first portion of the investigation surveys assistant district attorneys (‘ADAs’) regarding their beliefs in, and personal experience with a CSI Effect. While most ADAs believe an effect exists and has thwarted their own prosecutions, this Article shows that the majority of these cases resulted in convictions, thus disproving any CSI Effect. The second portion of the investigation is a plausibility study of the CSI Effect in which 538 mock jurors (comprised of 98 individuals on jury duty, 134 jury eligible adults, and 306 university students) deliberated to a verdict and identified (from a list) any reasons influencing it. The researcher then measured the CSI viewing habits of the mock jurors and scrutinized their verdict lists for evidence that CSI-oriented factors had entered into their decision-making. Presumably, frequent viewers of CSI operating under a CSI Effect would rely on CSI factors in their verdicts whereas infrequent viewers of the genre would not.

Contrary to the hype, the empirical data does not support the existence of a CSI Effect – at least not one that perverts guilty verdicts into wrongful acquittals. Indeed, the data shows that CSI-viewing mock jurors did not rely on CSI factors in reaching their verdicts (to any greater degree than did their non-viewing counterparts). In fact, only a very small portion of either group referenced such factors at all. Accordingly, it does not appear that there is a CSI Effect in light of the empirical data.”

The CSI Effect: Popular Fiction About Forensic Science Affects Public Expectations About Real Forensic Science, 47 Jurimetrics 357 (2007)
“Two of a number of hypotheses loosely referred to as the CSI Effect suggest that the television program and its spin-offs, which wildly exaggerate and glorify forensic science, affect the public, and in turn affect trials either by (a) burdening the prosecution by creating greater expectations about forensic science than can be delivered or (b) burden the defense by creating exaggerated faith in the capabilities and reliability of the forensic sciences. Surprisingly, no published empirical research puts these hypotheses to a test. The present study did so by presenting to mock jurors a simulated trial transcript which included the testimony of a forensic scientist. The case for conviction was relatively weak, unless the expert testimony could carry the case across the threshold of reasonable doubt. In addition to reacting to the trial evidence, respondents were asked about their television viewing habits. Findings: Compared to non-CSI viewers, CSI viewers were more critical of the forensic evidence presented at the trial, finding it less believable. Regarding their verdicts, 29% of non-CSI viewers said they would convict, compared to 18% of CSI viewers (not a statistically significant difference). Forensic science viewers expressed more confidence in their verdicts than did non-viewers. Viewers of general crime program, however, did not differ significantly from their non-viewing counterparts on any of the other dependent measures, suggesting that skepticism toward the forensic science testimony was specific to those whose diet consisted of heavy doses of forensic science television programs.”

A CSI Writer on the CSI Effect, 115 Yale L.J. Pocket Part 76 (2006)
“As one person who may be responsible for creating the CSI effect, I see both the upsides and downsides of this newsworthy phenomenon. On one hand, I have heard and read accounts of how CSI may have influenced juries to let potentially guilty defendants go free. I look at those cases as tragedies that should be troubling to us. On the other hand, better informed juries can’t be a bad thing. Interest in the sciences is a matter of national importance, and, thanks in part to television shows like CSI, young people are applying to forensic science programs in increasing numbers. And consider the consequences: If jurors had this level of knowledge and interest prior to the O.J. Simpson trial, we might have seen a different outcome. So when people ask me about the CSI effect, I tell them that it actually serves our government’s interest in education, and in justice.”

Impact of Television on Cross-Examination and Juror “Truth”, 14 Widener L. Rev. 479 (2009)
“Research demonstrates that jurors assess evidence and determine verdicts on the basis of stories, i.e., they assess truth in terms of the basic stories with which they are familiar. Consequently, cross-examination’s parameters and abilities must be considered within this context. In contemporary society, television is our primary storyteller: its stories, along with their component plots and stock characters, tell us how things work, define our culture’s morals, and provide a framework for interpreting events. This power also extends to the legal realm, for though few people have ever entered a courtroom, millions have seen one on TV. Consequently, television’s legal narratives can cultivate assumptions and expectations about law.

Referencing original empirical research regarding the influence of television representations of law-such as those of Judge Judy, CSI, and Law & Order-this paper explores the way in which television contributes to the stories that jurors use in structuring their determinations of ‘truth,’ as reflected in their verdicts. With this as a base, the paper discusses how televisual media will increasingly influence trials and, as a result, cross-examination. Consequently, in conducting cross- examination, attorneys will be obliged to acknowledge certain proven influences that television has on viewers while eschewing unsubstantiated mythologies about television’s influences.”

An Indirect-Effects Model of Mediated Adjudication: The CSI Myth, the Tech Effect, and Metropolitan Jurors’ Expectations for Scientific Evidence, 12 Vand. J. Ent. & Tech. L. 1 (2009)
“Part I of this article defines the ‘CSI effect’, given that the phrase has come to have many different meanings ascribed to it. It emphasizes the epistemological importance of first describing the effect of the ‘CSI effect’ as observed in juror behavior documented in a new study conducted in Wayne County (Detroit), Michigan, and then looking at causative factors that may be related to an explanation of those observed effects. Part II describes the methodology of the Wayne County study, provides a descriptive analysis of Wayne County jurors, and compares the jurors demographically to the Washtenaw County jurors who were surveyed in 2006. Part III analyzes the Wayne County study results with respect to jurors’ expectations and demands for scientific evidence. The Wayne County study findings reinforce the earlier Washtenaw findings of heightened juror expectations and demands for scientific evidence in almost every respect. This most recent analysis of the impact of viewing CSI or similar programs on jurors in Wayne County likewise reinforces the conclusions from the earlier Washtenaw County study that there is no such causative relationship between watching CSI and the heightened expectations and demands of jurors. Part IV explores the nature of the ‘tech effect’ as one causative factor for those heightened juror expectations and demands as an alternative to the ‘CSI effect.’ It also proposes an indirect-effects model of juror influences that combines the perception of a ‘CSI effect’ with the ‘tech effect’ of modern scientific advances and the generalized effect of media portrayals about crime. This model triangulates the potential interactive effects of a ‘CSI effect’ myth with the likelihood of a ‘tech effect’ in the context of the ‘mass mediated effects’ of law and order or crime and justice news. The results of regression analyses of data from Wayne County jurors provide some support for the 2006 study’s suggestion of a ‘tech effect’ — that the broader changes in popular culture brought about by rapid scientific and technological advances and widespread dissemination of information about them is a more likely explanation for increased juror expectations and demand for scientific evidence in the courtroom than simply viewing CSI or related programs. Part V provides an overview of contemporary perspectives of ‘mass-mediated effects’ on public attitudes, behaviors, and expectations as a prelude to the suggested Indirect-effects Model of Mediated Adjudication. ”

Investigating the “CSI Effect” Effect: Media and Litigation Crisis in Criminal Law, 61 Stan. L. Rev. 1335 (2009)
“How do we explain this apparent contradiction between media coverage and practice on the ground in U.S. criminal courts? There has been some excellent scholarly work debunking the CSI effect. There has also been some excellent work interpreting the program CSI itself. But there is little work that purports to explain the phenomenon of the CSI effect. In this article, we suggest that we may be able to gain additional insight into the CSI effect by drawing on legal literature emanating from an earlier episode of interaction between media and law. After all, the CSI effect is not the first time that American media has been accused of having perpetuated beliefs about the legal system that are not supported by empirical data. Since the 1970s, American media has reported on a phenomenon it termed the ‘litigation explosion’ or ‘litigation crisis.’ Legal scholars described this phenomenon as ‘hyperlexis,’ ‘litigation panic,’ and ‘litigation anxiety,’ among other things. Media reports claimed that litigation was increasing dramatically, that American litigation rates were much higher than those of comparable nations, that punitive damage awards were increasing rapidly, and that the legal system was out of control. In short, the litigation explosion was portrayed as an acute social problem, a ‘crisis.’ However, these claims have been widely debunked by socio-legal scholars, who have generally agreed that there has been no dramatic increase in American litigiousness or punitive damages, and that American litigation rates are not wildly out of line with those of comparable nations.

This Article will be modeled on this analogy with the litigation explosion literature. In the next Part, we will lay out a typology of effects that are all discussed in the media under the rubric of the CSI effect. In Part II, we will discuss the existing evidence in support of the most prominent of these effects, the claim that CSI is changing jury decision making. We show that there is scant empirical evidence to warrant concluding that such changes in jury decision making are occurring. We also introduce acquittal rate data that show only equivocal evidence of an increase in acquittals following the debut of CSI and its spinoffs and imitators. In Part III, we report results of a content analysis that shows that, like it was for the litigation explosion, media coverage is inconsistent with the lack of empirical evidence discussed in Part I. In Part IV and our Conclusion, we attempt to explain the CSI effect as a cultural phenomenon. In Part IV, we suggest that the CSI effect may be a ‘self-denying prophecy’ on behalf of prosecutors; in our Conclusion, we suggest that the CSI effect embodies anxiety about science’s threat to the law’s role in society as a truth-generating institution.”

Is the CSI Effect Good Science?, 115 Yale L.J. Pocket Part 73 (2006)
“At this time there is no scientific, empirical study that determines whether the CSI effect exists, or what it looks like. The Maricopa County prosecutors based their study on conversations with jurors after their trials. For this type of evidence to be credible we have to believe not only that jurors can accurately tell us if their verdict was influenced by particular knowledge about standards for evaluating evidence, but also that they know whether or not they acquired their information and standards from watching CSI. Psychologists are widely skeptical about people’s self-awareness on both counts, which is why they conduct controlled experiments. An experiment directly tests whether an experience, such as watching CSI, influences decisionmaking and is not biased by whether or not jurors know why they are acting as they do.

Although any changes to the legal system would be premature at this point given the lack of hard evidence, prosecutors have proposed a variety of remedies for the CSI effect, including asking about jurors’ viewing habits during jury selection, instructing jurors not to use CSI standards when evaluating scientific evidence, training prosecutors to make more sophisticated presentations of scientific evidence, and even explaining the CSI effect during their closing arguments. Before the legal system adopts changes to ‘solve’ this problem, it is important to engage in careful empirical assessment of whether, in fact, there is a problem to be solved.”

Media Use and Public Perceptions of DNA Evidence, Science Communication, Vol. 32, No. 1, 93-117 (2010)
“This study uses survey data to examine how various forms of media use are related to public perceptions of DNA evidence, including self-perceived understanding of DNA, perceptions of DNA evidence as reliable, weight attached to DNA evidence (or the absence thereof) in jury decision making, and support for a national DNA databank. The hypotheses build on cultivation theory, priming theory, and research regarding the ‘CSI effect.’ The findings indicate that overall television viewing, crime television viewing, and news media use predict perceptions of DNA evidence. Moreover, a question-order experiment produced evidence that priming thoughts about media can influence such perceptions.”

A Study of Juror Expectations and Demands Concerning Scientific Evidence: Does the “CSI Effect” Exist?, 9 Vand. J. Ent. & Tech. L. 331 (2006)
“Many prosecutors, judges and journalists have claimed that watching television shows like CSI have caused jurors to wrongfully acquit guilty defendants when no scientific evidence is presented. This is the first empirical study designed to investigate whether the CSI effect exists. This survey of 1027 persons called for jury duty in a State court looked at jurors’ television viewing habits, their expectations that the prosecutor would produce scientific evidence, and whether they would demand scientific evidence as a condition of a guilty verdict. While the study did find significant expectations and demands for scientific evidence, there was little or no indication of a link between those preconceptions and watching particular television shows. The authors suggest that to the extent that jurors have significant expectations and demands for scientific evidence, it may have more to do with a broader tech effect in our popular culture rather than any particular CSI effect. At the same time, this article contends that any such increased expectations and demands are legitimate and constitutionally based reflections in jurors of changes in our popular culture, and that the criminal justice system must adapt to accommodate jurors’ expectations and demands for scientific evidence.”

Symposium: The CSI Effect: The True Effect Of Crime Scene Television On The Justice System
(CSI Symposium at The New England School of Law Announcement, Crim Prof Blog, Oct. 6, 2006)

Viewing CSI and the Threshold of Guilt: Managing Truth and Justice in Reality and Fiction, 115 Yale L.J. 1050 (2006)
“The ‘CSI effect’ is a term that legal authorities and the mass media have coined to describe a supposed influence that watching the television show CSI: Crime Scene Investigation has on juror behavior. Some have claimed that jurors who see the high-quality forensic evidence presented on CSI raise their standards in real trials, in which actual evidence is typically more flawed and uncertain. As a result, these CSI-affected jurors are alleged to acquit defendants more frequently. This Review argues that, while some existing evidence on juror decisionmaking is consistent with the CSI effect, it is equally plausible that watching CSI has the opposite impact on jurors and increases their tendency to convict. The perceived rise in acquittals can also plausibly be explained without any reference either to watching CSI or to viewing crime dramas more generally. For these reasons, and because no direct research supports the existence or delineates the nature of the CSI effect, calls for changes to the legal system are premature. More generally, the issues raised by current attention to the CSI effect illustrate the problems that arise when proposed changes in the legal system are supported by plausible, but empirically untested, ‘factual’ assertions.”

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