The Problem with Bad Science

DNA has become the ultimate tool to identify the perpetrator of a crime. It is equally good at identifying the person who did not leave that evidence and is a valuable method to prove innocence as well as guilt. DNA has been able to exonerate many people who were wrongfully convicted. In many of those cases, innocent persons had been wrongfully convicted based on several traditional forensic science techniques. In almost a third of the exonerations, some form of forensic science was used to wrongfully convict them in the first place. This led Congress to commission the NAS to conduct a thorough study of the state of the forensic science in the United States. The 2009 NAS report concluded that, apart from nuclear DNA analysis, no other forensic method had been shown to consistently and reliably link evidence to a specific individual or source. The 350-page report found that many traditional forensic sciences lacked the empirical evidence to support their courtroom claims of individualization or identification.