Prosecutors have long complained about the CSI myth – the idea that a criminal case against a defendant can have such conclusive proof that there will be a CSI moment where the jury learns definitively of the defendant’s guilt. In voir dire, the process by which juries are selected by prosecutors and defense lawyers, prosecutors will often ask jurors whether they watch CSI, and whether they would required the prosecutors to provide such definitive proof.
The sad truth is, however, that the CSI myth works the other way: prosecutors and law enforcement sometimes offer forensic evidence – purportedly scientific evidence that says this bite mark, or that hair, or a shoe print, somehow links a defendant to a crime scene.
Sometimes the person testifying is from the vaunted FBI, that agency that still has such credibility, that even after years of investigations showing a failure of its crime lab to offer sound evidence, has the power to convict on its word alone.
The Justice Department and FBI have formally acknowledged that nearly every examiner in an elite FBI forensic unit gave flawed testimony in almost all trials in which they offered evidence against criminal defendants over more than a two-decade period before 2000.
and goes on to say:
The cases include those of 32 defendants sentenced to death. Of those, 14 have been executed or died in prison, the groups said under an agreement with the government to release results after the review of the first 200 convictions.