Our legal system depends heavily on scientific means-tests of blood samples, hair samples, and DNA-to ensure proper justice for the victims and the accused.

Late last week, however, the President’s Council of Advisors on Science and Technology (PCAST) released a report revealing that a great deal of courtroom evidence based on forensic methods, which had previously been considered trustworthy, often lacks sufficient scientific validation. In fact, we have little verification that many forensic techniques are actually proper forms of legal proof.

What Are the Consequences?

The PCAST report implicates a surprising number of standard forensic techniques, including:

  • Bite mark analysis
  • Footwear analysis
  • Firearms identification and analysis
  • Comparison of microscopic hairs

Simply put, these modalities are unreliable. Unfortunately, our criminal justice system has relied on them for a long while, with devastating consequences. The Innocence Project and the FBI recently conducted a joint study that demonstrated evidence stemming from hair and bite marks is often grossly misinterpreted; 95 percent of testimonies provided by hair examiners were found to be flawed.

Yet this faulty evidence has helped to convict innumerable individuals – many of them, as The Innocence Project has made clear, who were not responsible for any crime. In light of this, the Washington Post has called the PCAST study “a much-needed wake-up call to all who care about the integrity of the criminal justice system.”

What’s Being Done?

It would be difficult to make forensic evidence inadmissible. Countless courtrooms still trust in it, and its complete disavowal would be a lengthy and complicated undertaking.

And anyway, the PCAST report indicates that forensic evidence need not be thrown out entirely; but forensic disciplines must become more…disciplined-forensic studies, it’s suggested, must take more care to resemble real-world conditions (rather than considering a hair or toenail in isolation from other factors).

Until such steps are taken, individuals charged with crimes may find that the truth, whatever it is, cannot save them.