Imette St Guillen's dream was to be a crime scene investigator, just like the forensic experts she loved to watch as they solved the difficult cases on popular TV shows such as Law and Order and CSI. That flame was extinguished when Imette, a 24-year-old student at the John Jay College of Criminal Justice in Manhattan, was found bound, beaten and strangled in a New York alley last month, the victim of a brutal rape and murder that shocked the city. Now, in a huge twist of irony, the trial of the nightclub bouncer accused of killing her will concentrate heavily on the strong forensic evidence linking him to the crime. It will also reopen debate about the existence of what experts call the 'CSI effect', the concept in which American juries are perceived to bring what they see on the crime shows into the courtroom and look for overwhelming and often unrealistic forensic proof before being convinced of a person's guilt. 'The public is more interested in forensic evidence than ever before, largely because of these hugely entertaining TV shows,' said Professor Carol Henderson, director of the National Clearinghouse for Science, Technology and the Law at Stetson University College in Gulfport, Florida. 'Some jurors expect that some of the technology used in these shows is real, and it's not. Some of it just doesn't exist. Prosecutors feel there is an effect on jurors, and that these unrealistic expectations can harm the jury system.' Such a blurring of fiction and reality is unlikely to befall jurors in the St Guillen trial, according to Brooklyn district attorney Charles Hynes, because of the weight of the evidence against Darryl Littlejohn. The prosecution team, he said, had 'never seen a case where there has been so much forensic evidence as the foundation'. Yet the fact Mr Hynes is playing up details of those forensics - blood spots on ties that bound the victim's hands and rabbit and mink fur from tape around her head matching fibres from the collars of jackets found in the accused's flat - offer a clue to the way prosecutors are approaching such cases these days. Some fear juries are not only demanding irrefutable forensic proof that has been meticulously collected and investigated the way they see it done on TV, but that they also expect such evidence to be presented during a trial in such a way that captivates and entertains them. 'Television is meant to entertain and they are making things as dramatic as they can. But jurors can get conditioned by television and expect to see something that they think should be there,' Jeffrey Blitz, a prosecutor in New Jersey's Atlantic County, told The Press of Atlantic City. 'In many cases, we're bringing in an expert to explain to juries why evidence they think should be there isn't really there. In a sense, it's an expert we need to explain reality versus what's on television. If most people saw what our forensic investigators really go through, they'd be bored to death.' Such an expert might have come in handy in last year's Hollywood trial of actor Robert Blake, who was surprisingly acquitted of murdering his wife. 'They couldn't put the gun in his hand, there was no blood splatter, they had nothing,' jury foreman Thomas Nicholson said after the trial. Until now, evidence supporting the existence of the CSI effect has been largely anecdotal. But a team of criminologists at the University of Florida has just embarked on the first formal study of the effects of television-show forensics on the American juror, and hopes to report some of its findings by the summer. 'There's a uncertain amount of misinformation that may have a strong influence on our criminal justice system in various ways, particularly in the portrayals of forensic sciences on television, and jurors are perhaps the most susceptible to use this information in their decision-making,' said project director Dave Khey, who has previously lectured the American Society of Criminologists about forensic popular culture and its effects on juries. Other college studies have approached the phenomenon from a different perspective. Kimberlianne Podlas, a professor of media law at the University of North Carolina-Greensboro, presented a theoretical rape case to almost 300 students and asked them to rule on the defendant's guilt. Surprisingly, more guilty verdicts were returned by respondents who claimed to watch shows such as CSI only rarely than by frequent viewers, even though there was not enough forensic evidence to support a conviction. The results suggested that the CSI effect could actually work in favour of prosecutors, instead of against them. 'I expected it to go the opposite way,' Professor Podlas said. Another positive benefit is the sudden surge in the number of students wanting to take courses in crime scene investigation. 'There are schools who never had forensic science programmes before that are now doing them,' said Professor Henderson, a former assistant US Attorney. While no official figures have yet been compiled, she said she knew of one college in West Virginia that used to have five to 10 forensic science students but which now has 450. 'It's a good thing as long as there are proper checks and accreditations built in to guarantee the quality of the education,' she said. Yet despite this recent surge in popularity, and viewing figures that regularly reach 60 million in the US for CSI, and its two spin-off series, CSI: Miami and CSI: New York, Prof Henderson believes there is nothing new in the CSI effect. 'Perhaps you could call it the Quincy effect,' she said, referring to 1970s drama series about a crime-fighting coroner who pushed the boundaries of his job by investigating cases instead of just examining the bodies. 'Quincy didn't have as many bells and whistles as CSI or Law and Order, but it gave people unrealistic ideas about what a medical examiner would do,' she said. 'It showed that pop culture and celebrities do have an effect on the way people think.'