Faulty forensic evidence causes 24% of wrongful convictions

The problem isn’t new. Experts have recognized for more than a decade that much of the forensic science we rely on in criminal cases is flawed or unreliable. In 2009, the National Research Council issued a report to the Justice Department, finding that a great deal of forensic science, especially pattern-matching evidence, is not based on sound scientific principles at all. Further, forensic analysts routinely exaggerate the surety of their findings in criminal cases. That report was a blockbuster.

In 2016, the President’s Council of Advisors on Science and Technology (PCAST) followed up with its own report. PCAST found again that many common forensic techniques need to be studied for foundational reliability. Furthermore, the industry lacks clarity and standards for reliability and validity.

Despite these findings, forensic science continues to be widely used in criminal cases.  Juries continue to believe that the science is reliable and performed in a fair, neutral way. However, the reality is often quite the opposite. Forensic tests are almost always performed by police or state crime labs, and state crime labs are incentivized to help the police, not defense attorneys.

Now, a new law review article argues that we need a systemic overhaul of forensic science in the U.S. The forensic sciences field is “beyond ‘reform’ in the sense that tweaks around the edges cannot fix it,” says the author, university of Maryland law professor Maneka Sinha.

Forensic science does not rely on peer review for accuracy

There is some hard research being done in an attempt to validate forensic science, and this hard science is subject to peer review, the gold standard. However, the kind of meat-and-potatoes forensic science that is done by police and crime labs is not subject to peer review. Sinha supposes this is partly due to the prosecution’s desire to maintain convictions rather than searching for ways their evidence could be wrong.

“Instead, forensic scientists often receive positive feedback for their work, regardless of the accuracy of their findings,” Sinha says.

People of color may be disproportionately harmed

Interestingly, Sinha found that, when people are exonerated after faulty forensic evidence was used to convict them, a pattern emerges. Among those exonerated for this reason, 54% were African-American or Latino. In essence, bad forensic science is used more often against defendants of color.

Sinha believes the reason is the halo that forensic science is often viewed as having. Juries often assume that forensic science is more neutral than other types of evidence and think that quality controls and peer review support the evidence.

Skip to content