The CSI effect is the name given to the phenomenon by which it is said that the television series Crime Scene Investigation (CSI), which debuted in October 2000, together with its later spin-offs, CSI: Miami and CSI: New York, otherwise known collectively as the 'CSI franchise', have changed the way in which the criminal justice system operates. The phrase was coined, or at least publicised, by the journalist Richard Willing, whose story '"CSI Effect" Has Juries Wanting More Evidence' appeared in USA Today on the 5th August 2004.

This report recounted the story of the trial of one Robert Durst, who was accused of murdering his neighbour Morris Black and dismembering the body before disposal. Although Durst admitted killing Black, he claimed that it was self-defence, and since Black's head was never found, the defence claimed that, had it been found, then a forensic examination of the head would have supported the claim of self-defence. The defence employed a jury consultant named Robert Hirschhorn who specifically wanted jurors who were familiar with shows such as CSI because he felt that they would be best able to appreciate this "gap in the evidence". Since Durst was later acquitted of murder, the case was cited by Richard Willing as "an example of how shows such as CSI are affecting action in courthouses across the USA" in what "prosecutors, defence lawyers and judges" were calling "the CSI effect".

However, as was identified in Willing's original article, there are variety of ways in which it has been alleged that television is affecting the criminal justice system, and thus a multiplicity of alleged CSI effects.

1. The effect on juries

The first claim is that exposure to shows such as CSI has changed the way in which juries consider forensic evidence. There is, however, no consensus as to the nature of this change, as both defence and prosecution have claimed that the CSI effect is hindering their side of justice. In fact a number of alternative theories have been put forward.

Hypothesis A is that the CSI has raised the public's expectations for the kind of forensic evidence that could and should be offered at trials to such heights that jurors are disappointed by the actual evidence with which they are presented. Hypothesis B is that CSI has fooled jurors into thinking that forensic science is far more effective and accurate than it actually is, whilst Hypothesis C is that CSI has increased interest in forensics and science and that jurors are therefore more interested in and better able to follow scientific evidence presented in court. (Although strangely enough, no one appears interested in putting forward Hypothesis D, which is that it has made no difference whatsoever.)

Although attempts have been made to establish which of these hypotheses is most likely to be true, the results have been somewhat mixed. One Kimberlianne Podlas published research that sought to expose the whole notion of any CSI Effect as a media myth, only for her research to be comprehensively rubbished by N.J. Schweitzer and Michael J. Saks, who claimed that she had deliberately selected a hypothetical case that was designed to render forensic-science evidence irrelevant. Their research alternatively concluded that "CSI viewers were more critical of the forensic evidence presented at the trial, finding it less believable" than those who watched Law and Order, for example. Other researchers at Eastern Michigan University concluded that although jurors had higher expectations of forensic evidence as a result of watching CSI it didn't appear to effect the decisions they reached.

Which, if any, of the three hypotheses is valid is therefore not known. Indeed the answer may well be all three, depending on who you're talking to. One of the problems being that there is little or no research relating to how jurors assessed forensic evidence prior to the arrival of CSI. So as far as the conclusion reached by Schweitzer and Saks is concerned, it might therefore simply be the case that people who are more critical of forensic evidence are also the kind of people who prefer CSI to Law and Order. Indeed according to a certain Professor Tom R. Tyler, since there is there is "no existing empirical research" which "shows that it actually occurs", he has argued that the CSI effect has only "become an accepted reality by virtue of its repeated invocation by the media".

None of which has of course prevented lawyers from advancing the argument when it suits their purpose. As in the case of the People v. Noriega, where the assistant district attorney of Santa Barbara County in California, one Christie Stanley, was faced with the problem of explaining how a thirty year-old defendant with a "minimum education" had allegedly committed murder without leaving any forensic trace whatsoever. Ms Stanley simply claimed that the defendant had learnt how to do so "from watching TV".

2. The effect on victims

It has also been argued that CSI has led to unrealistic expectations from victims and their relatives as to both the capabilities and timescales involved in a police investigation. It has been said that such people are often perplexed as to why the police seem unwilling to deploy the same level of high-tech wizardry as their television heroes, and become frustrated to learn that it often takes days if not weeks for evidence to be analysed at the laboratory, compared to the few minutes or so it takes Grissom and company to generate a DNA match and identify a suspect. Again there appears to be little or no direct evidence that this has occurred other than various anecdotal reports from investigative agencies and, in any case, one suspects that previous generations were similarly disappointed when detectives failed to display the same intellectual acumen as Sherlock Holmes.

3. The effect on criminal behaviour

It was once a cliché in British crime drama for the lead detective investigating some particularly heinous murder to claim that the lack of forensic evidence at the murder scene could be explained by the fact that the murder had been committed by a policeman, or someone familiar with forensic science. Or indeed, as some of us used to point out at the time, someone who simply watched a lot of British crime drama. Similarly it has been claimed that those predisposed to the commission of criminal acts have been avidly watching CSI and generally absorbing the information imparted on how not to get caught, and have subsequently put what they have learnt into practice.

For example one Ray Peavy, who was in charge of the homicide unit for the Los Angeles County Sheriff's Department in 2006, has complained that evidential items "like cigarette butts, coke cans, beer cans, a sweaty hat band or blood or semen, hairs" once a rich source of forensic evidence, were "no longer being left at crime scenes". Similarly, and more mischievously, the Manchester Police in the United Kingdom have reported that car thieves frequently collect cigarette butts and leave them in stolen cars before they abandon them, so that the police then waste time and resources obtaining DNA results for multiple irrelevant suspects, whilst there are various anecdotal accounts that claim that investigators often find that the crime scene has now been blasted clean of evidence.

Although there are those who have cited cases where criminals have tried and failed to cover up their crimes using techniques they learned from television as evidence that such things do not work, it is not possible to say whether there are any criminals who have watched CSI and later managed to get away with their crimes as a result of what they learned, since such individuals would obviously be reluctant to come forward and trumpet their success.

There are those that are dismissive of the whole idea that criminals can profit from such efforts. One Barry Fisher, director of the Los Angeles County Sheriff's Department crime lab, has claimed that "It is categorically impossible for someone to get rid of all of the evidence that someone leaves at a crime scene. They can try, but they are not going to succeed in covering it all up." In the same vein Guy Rutty, of the Forensic Pathology Unit at the University of Leicester, has cited an experiment where a volunteer simply entered a sterile room, walked around and repeated a phrase, but it nevertheless proved possible to retrieve the subject's DNA even though the volunteer had been in the room for only a few seconds and was wearing a face mask of the kind used by crime scene investigators. Sadly for Mr Rutty, few crimes are actually committed in sterile rooms, and so the value of such evidence in terms of the criminal law is almost nil.

Such exaggerated claims regarding the capabilities of forensic science are not uncommon, despite the existence of repeated instances of crimes where the perpetrators have indeed succeeded in "covering it all up", as in the case of People v. Noriega previously mentioned, as well as that of the Ipswich Red Light Murders, where the police were at a complete loss when faced with the discovery of the first two victims, due to the complete lack of any forensic evidence left by the perpetrator. (A note for would be serial killers; dump the body in running water, it really does wash away all your sins.)

4. The Career effect

As it turns out the one undisputable CSI effect is that it has made the business of crime scene investigation 'sexy'. American universities have therefore seen an increase in the number of students who wish to study forensic science and pursue a career in the field. (Although one suspects that some students may well be disappointed to learn that real CSIs don't generally speaking get to interview suspects or indeed chase them around the place with their guns drawn, and that there are such people as police detectives who are actually in charge of criminal investigations.) It has also been said that by increasing the profile of forensic science, CSI has also encouraged increased research and investment in the field. This is particularly since a good deal of the forensic science portrayed by CSI is 'speculative' rather than real science, as in the infamous 'spray-on condom', in that it portrays scientific techniques that don't actually exist, but possibly might if someone came up with the money.

In the long term, it is the effect on criminal behaviour that is likely to be the most significant, notwithstanding the protestations made by some.

Since its first application to a criminal case in 1985, the science of DNA has had a considerable effect on the criminal justice system. No one would doubt the claim that investigators and prosecutors have 'changed their behaviour' as a result of the availability of DNA evidence, and no one should doubt that those who commit crimes will (to the extent that they have not done so already) eventually change their behaviour as well. Indeed the idea that offenders can learn to be better criminals is not a totally revolutionary concept. The science of fingerprinting was once hailed as an all-powerful weapon in the fight against crime, in the same way as DNA evidence has recently been accorded the same accolade. Of course the value of fingerprinting as a forensic technique has declined over time as criminals have adopted such simple techniques as wearing gloves when committing crimes, wiping down surfaces, or torching motor vehicles used during the commission of a criminal act. In a similar fashion people will, over time, learn how not to leave their DNA at crime scenes. You can blame CSI for that development, or simply accept the fact that it would have happened anyway.


  • Richard Willing, "CSI Effect" Has Juries Wanting More Evidence, USA Today, August 24 2004
  • N.J. Schweitzer and Michael J. Saks, The CSI Effect: Popular Fiction About Forensic Science Affects the Public’s Expectations About Real Forensic Science, 47 Jurimetrics J. 357–364 (2007).
  • Leonard Post, Prosecutors Say TV-Savvy Criminals Benefit From 'CSI Effect', The National Law Journal, February 17, 2006

Log in or register to write something here or to contact authors.