In recent decades, prosecutors have relied on a wide range of forensic science techniques to provide crucial evidence in pursuing criminal convictions. Several of those techniques, however, have not withstood scientific scrutiny. As a result, many individuals have been convicted on the basis of fundamentally flawed forensic evidence – a pattern reflected in the increasing number of exonerations based on improper forensic testimony.
In recent years, scientists have uncovered disturbing flaws in forensic science practices including arson science, firearms ballistics, hair microscopy, and analysis of fingerprints, bite marks, and blood stains. Forensic examiners have routinely overstated the significance of such evidence in court, improperly bolstering the weight of evidence used to support convictions. The systemic flaws in forensic science techniques were described in detail in a 2009 report by the National Academy of Sciences and a 2016 report by the President’s Council of Advisors on Science and Technology – those reports reflected the strong scientific consensus that many forensic techniques routinely presented by prosecutors actually lack sufficient reliability to be considered sound science. Outside of the courtroom, crime laboratories across the nation have faced scandals due to the misconduct of forensic analysts. In one high-profile example, the Massachusetts Supreme Judicial Court dismissed over 21,000 drug cases after a state examiner admitted to fabricating drug analyses for nearly a decade. These flaws in the forensic science system threaten the integrity of the broader criminal justice system and create an unjustifiable risk of wrongful convictions.