I titled this book Failed Evidence for a simple reason. Evidence is the proof of facts lawyers use to prove matters in court. Evidence can take many forms: the statements of the defendant to the police, eyewitness identification testimony, and the results of forensic testing., to name just three important categories.
Twenty-five years ago, before I became a law professor, I was trying cases as a criminal defense attorney and (more briefly) as a prosecutor. Confessions, eyewitness identifications, and forensic tests were, for the most part, unassailable. Then came the DNA revolution, beginning in 1989. With DNA , we could identify the real perpetrator from trace amounts of bodily fluids, with a degree of certainty formerly unimaginable. But we also learned that, in many cases, routine types of evidence had convicted the innocent. DNA proved it, just as it had proved the guilt of others.
We now have decades of scientific work and evaluation on confessions, eyewitness identification, and forensics, and we have learned something disturbing: many of our traditional methods of conducting investigations create risks of miscarriages of justice. Thus, for some of our most common ways of gathering evidence, we fail in an unacceptable number of cases.
But it is the book’s subtitle — Why Law Enforcement Resists Science — that brings the the real failure into focus. For example, almost four decades of solid science tells us that showing an eyewitness a lineup of similar-looking people — think of any lineup in the movies or on TV that you’ve ever seen — produces a risk of mis-identification. The science also tells us that we can reduce this risk considerably by showing the people in the lineup to the witness not simultaneously, but sequentially: one at at time. But most of law enforcement — both police agencies and prosecutors’ offices — have refused to embrace the science and the improved practices this would create. A few jurisdictions — New Jersey, for example — have changed their procedures based on the science, but they remain a distinct minority. Most agencies continue to actively resisting any change.
Failed Evidence explains why law enforcement has resisted the scientific work that looks into its most basic tasks, even in the face of DNA-based proof that improvement is badly needed. Failed Evidence then lays out concrete strategies for overcoming the resistance, with examples of success.
So, for me, Failed Evidence seemed like the only logical choice for a title.