Scientific Evidence That’s Not So Scientific

Professor Gordon has spent the last several years focusing on the ways in which old ideas and myths about alcohol and substance use have impacted individuals who are diverted out of the criminal justice system and into drug and other specialty courts. But myths and their effect on decision making are of course not limited to substance use, and Professor Gordon is going to spend this summer writing about the admission of forensic feature comparison methods in criminal trials¾these are the forensic methods that allow experts to match things like bitemarks or latent fingerprints to a criminal defendant.

In the last twenty or so years, we’ve seen hundreds of convictions reversed based on faulty forensic comparison methods, everything from DNA evidence to bitemark evidence. Latent fingerprint analysis, for example, was first used to identify criminal defendants in the 1800s. In 1984, the Department of Justice noted that “of all methods of identification, fingerprinting alone has proved to be both infallible and feasible.” As it turns out, however, the validity of latent fingerprint identification has been assumed – but not proven - for almost 200 years. According to the most recent President’s Council of Advisors on Science and Technology Report on Forensic Science in Criminal Courts, there have only been two appropriately-designed studies assessing the validity and reliability of latent prints – the first was published by the FBI in 2011 and the second was completed in 2014. Both studies found much higher false positive rates than the general public assumes, especially given our longstanding expectations about the infallibility of this type of forensic evidence. Notwithstanding these concerns, courts continue to admit this type of evidence in criminal trials and allow experts to assure legal decision makers of its infallibility.

This piece will focus on the reluctance of these legal decision-makers to embrace challenges to longstanding ideas or practices, even in the face of credible scientific evidence suggesting that the old approaches might be incorrect or misinformed.