While it’s now widely accepted that some forensic disciplines, like microscopic hair comparison, are junk science, evidence from similarly subjective pattern-matching disciplines still gets into courtrooms. There are standards meant to prevent this, but they aren’t working, which can contribute to wrongful convictions. According to legal experts, what’s necessary is stopping bad science before it gets to court.
In 2009, a sweeping report from the National Academy of Sciences revealed the questionable nature of the pattern-matching forensic disciplines. These disciplines involve an expert comparing a piece of evidence—like the structure of a hair or a fingerprint—to a sample from a suspect. But no scientific research shows that such analyses can definitively link a person to a crime, and there’s no research supporting the reliability of these methods.
One recommendation from both reports is establishing independent crime labs, rather than rely on labs under the control of law enforcement. “By the time [evidence] gets to a judge, in some ways it’s sort of too late,” said Brandon Garrett, a law professor at Duke University who specializes in criminal justice outcomes, evidence, and constitutional rights. “You already may have someone arrested, potentially pleading guilty based on the forensics. We need to focus on improving the science in the laboratories.”