The wrongful conviction of forensic science
The purpose of this study was to examine the accuracy of claims that faulty forensic science is a leading cause of wrongful convictions. This sentiment has been reported at length by major news outlets across the United States. It has also been a matter of great concern to a group of activists in what is known as the innocence network and other individuals having varying degrees of interest in the formulation of public policies related to forensic science.
To meet the objectives of this study, its authors reviewed past research and public information pertaining to the first 200 DNA exonerations that occurred between 1989 and 2007. The frequencies of systemic failures extracted from case profiles published by the Innocence Project were tabulated and analyzed with due consideration given to media reports that summarized individual cases. Authoritative texts were also consulted to help put the issue of wrongful convictions in proper context.
As a result of this study, forensic science malpractice, whether intentionally or accidentally committed, was shown to be a comparatively small risk to the criminal justice system—accounting statistically for less than 11 percent of all cases studied. As the authors will explain, the true percentage is likely much lower. But just as compelling were the number of wrongful convictions (18 percent) where forensic evidence reportedly favored the defendant.
In this regard, the available data strongly indicate that complaints about the overall quality of forensic science in American jurisprudence are mainly rhetorical in nature and are not based on valid statistical analyses of the role of forensic science in overturned convictions. While the profession of forensic science, like all critical professions, has a responsibility to continuously improve itself, its portrayal in the media as generally having an adverse impact on our criminal justice system is an injustice.