Prosecutors are ignoring new research debunking popular science used to convict people

We may earn a commission from links on this page.

A new White House report this week concluded that some of the most common forensic science techniques used to convict criminal defendants are unreliable. The Attorney General, Loretta Lynch, and an association of local prosecutors have decided to ignore the findings.

The President’s Council of Advisors on Science and Technology, a farm team of some of the smartest scientific minds in the country, released a report Tuesday calling into question the analysis of bite marks, shoe prints, hair samples, and other forensic techniques regularly used by police departments around the country. After reviewing years of studies, the report determined that these methods either have little backing in current scientific evidence or often are represented in ways that overstate the certainty of their conclusions. Only basic DNA analysis is truly scientifically reliable, the report found.


Those conclusions are hugely significant and should act as a wake-up call to forensic examiners around the country, said Barry Pollack, the president of the National Association of Criminal Defense Lawyers. "These are not rare exotic types of examinations—there are forensic examiners around the country who every day testify about bite marks or shoe prints or hair analysis," he told me.

The nation's top prosecutors are rejecting their conclusions. Quickly after the report was released, Attorney General Loretta Lynch told the Wall Street Journal that “we remain confident that, when used properly, forensic science evidence helps juries identify the guilty and clear the innocent, and the department believes that the current legal standards regarding the admissibility of forensic evidence are based on sound science and sound legal reasoning. While we appreciate their contribution to the field of scientific inquiry, the department will not be adopting the recommendations related to the admissibility of forensic science evidence.”


The National District Attorneys Association, which represents local prosecutors around the country, released an even stronger statement: "PCAST has taken it upon itself to usurp the Constitutional role of the Courts and decades of legal precedent and insert itself as the final arbiter of the reliability and admissibility of the information generated through these forensic science disciplines," the association said. "PCAST has determined to throw away and ignore years of settled law and to act as both judge and jury in urging the exclusion of forensic science disciplines in the courtrooms of our nation."

Pollack compared the prosecutors' response to "someone who still believes the world is flat or questions whether our climate is changing."

"The fact of the matter is that there is such a thing as valid science, there's also such a thing as junk science, and there's a difference between the two," he said.

Neither the White House nor the advisory council's staff responded to requests for comment about how the report was being received. Several of the law professors who consulted on the report also did not respond to requests for comment.


While the report stated that it wasn't explicitly calling into question past convictions based on forensic science techniques, it could serve as a strong impetuous to exonerate some defendants. Federal law, however, makes it difficult for federal courts to review state convictions.

There may be a greater chance for reform at the state level. Notably, a 2013 Texas law allowing for post-conviction hearings for inmates convicted based on now-debunked science has led to numerous stays of execution in the past year. Inmates whose convictions were based on now-questioned scientific theories, like Shaken Baby Syndrome, have won reprieves. There's also been progress in California: William Richards was convicted of murdering his wife in San Bernardino mostly because of expert testimony that a mark on her hand came from a bite that matched the pattern of Richards’ teeth. He served 23 years in prison before being exonerated by the California Supreme Court in May.


Ironically, the elected prosecutor in the district where Richards was convicted, Michael Ramos, is now the president of the National District Attorneys Association, and has attacked the White House report on Twitter:


Even if prosecutors ignore the panel's findings, defense lawyers can use them to cast doubt upon forensic evidence against their clients. Perhaps the most importance audience for the report is judges, who determine what scientific evidence can and can't be admitted during a trial. The report's authors were advised by some of the most prominent jurists in the country, including the former Chief Judge of the Ninth Circuit Court of Appeals, Alex Kozinski, who wrote an op-ed supporting it in the Wall Street Journal, labeling forensic techniques "voodoo science."

"Bitemark analysis is about as reliable as astrology," he wrote, "yet many unfortunates languish in prison based on such bad science."


Judges tend to listen to what other judges say. Pollack predicted that trial judges would give credence to the White House scientists, and "prosecutors can lead on this issue or they can come along kicking or screaming."

Casey Tolan is a National News Reporter for Fusion based in New York City.