Influence of forensic science fiction on public perceptions
The CSI effect describes the various ways in which the exaggerated portrayal of forensic science on crime television shows such as "" influences public perception. The term was first reported in a 2004 "USA Today" article describing the effect being made on trial jurors by television programs featuring forensic science.
It most often refers to the belief that jurors have come to demand more forensic evidence in criminal trials, thereby raising the effective standard of proof for prosecutors. While this belief is widely held among American legal professionals, some studies have suggested that crime shows are unlikely to cause such an effect, although frequent "CSI" viewers may place a lower value on circumstantial evidence. As technology improves and becomes more prevalent throughout society, people may also develop higher expectations for the capabilities of forensic technology. The CSI effect has also re-popularized the forensic sector of the criminal justice system in the media and academia.
Background.
The CSI effect is named for "", a television program which first aired in 2000. In "CSI", a fictional team of "crime scene investigators" ("CSIs") solve murders in the Las Vegas metropolitan area. In each episode, the discovery of a human corpse leads to a criminal investigation by members of the team, who gather and analyze forensic evidence, question witnesses, and apprehend suspects. 
The fictional show's popularity led to three spin-offs: ', which debuted in 2002, ', first aired in 2004, and ', which premiered in 2015. In 2021, a new spinoff aired, ', which brought back William Petersen and Jorja Fox, replaying their original roles as Gil Grissom and Sara Sidle, respectively. 
The "CSI" franchise's success resulted in the production of many similar shows. The "CSI effect" has been associated with drama and true crime television series that preceded "CSI", such as "American Justice", "Cold Case Files", "Cold Squad", "", "Forensic Files", "Silent Witness", "Waking the Dead"; and others that followed, including "Bones", "Cold Case", "Criminal Minds", "Crossing Jordan", "NCIS", "Numb3rs", "Wire in the Blood", and "Without a Trace". 
Based on the Nielsen ratings, six of the top ten most popular television shows in the United States in 2005 were crime dramas, and "CSI: Crime Scene Investigation" reached the number one ranking in November 2007.
Several aspects of popular crime shows have been criticized as being unrealistic. For instance, the show's fictional characters not only investigate ("process") crime scenes, but they also conduct raids, engage in suspect pursuit and arrest, interrogate suspects, and solve cases — which, in real life, falls under the responsibility of detectives and uniformed officers, not CSI personnel. Additionally, if CSIs process a crime scene, it is inappropriate for them to also be involved in the examination and testing of any evidence collected from that scene as it would compromise the impartiality of scientific evidence. In real investigations, DNA and fingerprint data are often unobtainable and, when they are available, can take several weeks or months to process, whereas television crime labs usually get results within hours.
In the first season of "CSI", technicians made a plaster mold of the interior of a wound to determine the type of knife used to make the wound, which is not possible with current technology. Characters on television often use the word "match" to describe a definitive relationship between two pieces of evidence, whereas real forensic technicians tend to use terms that are less definite, which acknowledges that absolute certainty is often not possible.
Anthony E. Zuiker, creator of the "CSI" franchise, claimed that "all of the science is accurate" on the shows; researchers, however, have described "CSI"'s portrayal of forensic science as "high-tech magic". Forensic scientist Thomas Mauriello estimated that 40 percent of the scientific techniques depicted on "CSI" do not exist. In addition to using unrealistic techniques, "CSI" ignores all elements of uncertainty present in real investigations, and instead portrays experimental results as absolute truth.
The notion that these inaccurate portrayals could alter the public perception of forensic evidence was dubbed the "CSI effect", a term which began to appear in mainstream media as early as 2004.
Under this effect, victims and their families – and jurors – are coming to expect instant answers from showcased techniques such as DNA analysis and fingerprinting, when actual forensic processing often takes days or weeks, with no guarantee of revealing a "smoking gun" for the prosecution's case. District attorneys state that the conviction rate in cases with little physical evidence has decreased, largely due to the influence of "CSI" on jury members.
By 2009 more than 250 stories about the CSI effect had appeared in newspapers and magazines, including articles in "National Geographic", "Scientific American", and "U.S. News &amp; World Report".
Research findings.
Although the CSI effect is a recent phenomenon, it has long been recognized that media portrayals of the United States legal system are capable of significantly altering public awareness, knowledge, and opinions of it. 
An attorney told "The New York Times" in 1990 that "Any lawyer who doesn't watch "L.A. Law" the night before he's going to trial is a fool". A 2002 juror survey showed that viewers of the popular court show "Judge Judy" were greatly misinformed about the purpose of the judge within a courtroom. 
Earlier programs which may have affected public perception of "the legal or investigative systems" include "Perry Mason" (1957–1966), "Quincy, M.E." (1976–1983) and the "Law &amp; Order" franchise (1990–present). 
News media reports on criminal trials, extensive internet blogging, and the successes of the Innocence Project have also contributed to the increased public awareness of forensic science. "CSI" franchise creator Zuiker has stated that "'The CSI Effect' is, in my opinion, the most amazing thing that has ever come out of the series."
The CSI effect is described by researchers N. J. Schweiter and Michael J. Saks as a reference to the alleged phenomenon of "CSI" raising crime victims' and jury members' real-world expectations of forensic science, especially crime scene investigation and DNA testing. Donald E. Shelton, Young S. Kim and Gregg Barak have said it has changed the way many trials are presented today, in that prosecutors are pressured to deliver more forensic evidence in court.
In 2006, the evidence cited in support of the supposed effect was mainly anecdotes from law enforcement personnel and prosecutors, and allegedly little empirical examination of the effect had been done, and the one study published by then suggested the phenomenon may be an urban myth. A study in 2008 using psychology graduate students found no evidence of the CSI effect among heavy viewers of these types of programs. 
A survey conducted by Donald E. Shelton on 1,027 potential jurors in Ann Arbor, Michigan revealed that while "CSI" viewers had higher expectations for scientific evidence than non-"CSI" viewers, in most cases, scientific evidence was not needed in order to reach a verdict.
However, more recent research suggests that these modern TV shows do have a misleading influence on public perceptions and expectations, and juror behavior.
Citing the "CSI effect", at least one researcher has suggested screening jurors for their level of influence from such TV programs.
Cultivation theory.
Many studies on the "CSI effect" cite George Gerbner's cultivation theory to explain the effects that consuming television may have on viewers' perceptions of reality. Gerbner's theory claims that television is a centralized system of storytelling and causes the distortion of reality. Cultivation Theory argues that the more time people spend "living" in the television world, the more likely they are to believe social reality aligns with the "reality" portrayed on television. The theory suggests that those who watch more television are more likely to develop certain beliefs about reality based on the various depictions shown on television.
One study applied Gerbner’s Cultivation Theory to college students to see if the United States' crime shows distorted their perception of reality. Students who had heavily viewed U.S. crime shows were found to be more likely to believe various misconceptions of reality, such as how likely one is to get attacked at night in the United States. 
Another study applied Gerbner's theory to a content analysis of popular crime dramas like ", , Criminal Minds", and "Without a Trace." Researchers found that DNA was frequently referenced within these shows, which supports with the argument that cultivation in fictional media had real-world consequences.
Manifestations.
Trials.
The popularity of forensic crime television shows supposedly gives rise to many misconceptions about the nature of forensic science and investigation procedures among jury members. The CSI effect is hypothesized to affect verdicts in two main ways: 
While these and other effects may be caused by crime shows, the most commonly reported effect is that jurors are wrongly acquitting defendants despite overwhelming evidence of guilt. In particular, prosecutors have reported feeling pressured to provide DNA evidence even when eyewitness testimony is available. 
In fact, in a study of 444 prosecutors, 56% believed the CSI effect to almost always or always influence juries, and 81% believed the CSI effect to influence judges. 
In one highly publicized incident, Los Angeles County, California District Attorney Steve Cooley blamed actor Robert Blake's acquittal on murder charges on the CSI effect. Cooley noted that the "not guilty" verdict came despite two witness accounts of Blake's guilt, and claimed that the jury members were "incredibly stupid".
By 2005, some judges and prosecutors had begun altering their trial preparations and procedures in an attempt to counter the CSI effect. 
Some ask questions about crime drama television viewership during "voir dire" to target biased jurors. 
For example, in "Charles and Drake v. State" (2010), the defendants were convicted of second degree murder, and during "voir dire", the judge presented a question about the CSI effect. In this case, the Maryland appellate court ruled the CSI effect "voir dire" question inappropriate due to its biased language and use of the term "convict" without mention of acquittal. 
Prosecutors have also used opening statements and closing arguments to minimize the possible impact of the CSI effect. 
In "Goff v. State" (2009), the prosecutor asked jurors during "voir dire" about their ability to render a verdict without scientific evidence, and then reminded them during closing arguments about this question. In this case, the mention of the CSI effect was considered acceptable because the language used was neutral and unbiased.
Additionally, jury instructions have also been used as a means of informing jurors about the CSI effect. 
In "Atkins v. State" (2011), the jury was instructed that scientific evidence is not necessary for a case to be valid. The court ruled that this jury instruction regarding scientific evidence was improper because the State was not held to its burden of proof. 
Furthermore, prosecutors have hired expert witnesses to explain why particular forms of physical evidence are not relevant to their cases. In one Australian murder case, the defense counsel requested a judge-only trial to avoid having DNA evidence misinterpreted by a jury. 
In addition to having to add questions during voir dire and making opening and closing statements, prosecutors are spending more time during the jury selection process in order to avoid choosing jury members who regularly watch crime-based television shows.
By 2006, the CSI effect had become widely accepted as reality among legal professionals, despite little empirical evidence to validate or disprove it. 
A 2008 survey by researcher Monica Robbers showed that roughly 80% of all American legal professionals believed they had had decisions affected by forensic television programs.
New York University professor Tom R. Tyler argued that, from a psychological standpoint, crime shows are more likely to increase the rate of convictions than acquittals, as the shows promote a sense of justice and closure which is not attained when a jury acquits a defendant. The perceived rise in the rate of acquittals may be related to sympathy for the defendant or declining confidence in legal authorities. 
A 2006 survey of U.S. university students reached a similar conclusion: the influence of "CSI" is unlikely to burden prosecutors, and may actually help them.
One of the largest empirical studies of the CSI effect was undertaken in 2006 by Washtenaw County Circuit Court Judge Donald Shelton and two researchers from Eastern Michigan University. They surveyed more than 1,000 jurors, and found that while juror expectations for forensic evidence had increased, there was no correlation between viewership of crime shows and tendency to convict. 
One alternate explanation for the changing perception of forensic evidence is the so-called "tech effect": as technology