Let’s Keep the Science in Forensic Science

The following article by Sunita Sah and others* was published by Scientific American, October, 2017 issue.

A body created to set national standards is now in danger

Keith Allen Harward served 33 years in jail after being convicted of rape and murder, largely on the strength of bite-mark evidence. He was subsequently found to be innocent on the basis of DNA and released. When he was incarcerated, the man considered the likely perpetrator remained free.

This miscarriage of justice was the result of bad science. Bite-mark evidence has been shown to lack any scientific credibility, yet it continues to be used in court. To a public accustomed to watching crimes being solved on television shows, where the results are always pristine and the guilty are always convicted, there is a perception that forensic science is flawless. The reality is that it is not, and we are in danger of halting and even reversing the considerable steps that have been taken to fix it.

In 2009 the National Research Council evaluated the state of forensic science and, shockingly, concluded that many of the techniques used in court actually have no scientific basis. In response, in 2013 the Department of Justice established the National Commission on Forensic Science (NCFS), which was directed to explore these issues and make recommendations for addressing them. Administered jointly by the DOJ and the National Institute of Standards and Technology, the commission—of which we are members—has worked diligently over the past four years to identify problems and propose changes to strengthen forensic science.

This work now may become undone. On April 10 the DOJ, under the new attorney general Jeff Sessions, refused to extend the term of the NCFS, which brought together diverse stakeholders, including forensic scientists, judges, lawyers, victims' advocates, law enforcement and practicing independent scientists. Its formal demise came a couple of weeks later. This is a tremendous missed opportunity for the progress of forensic science and criminal justice. During its four years of operation, the NCFS made strides in bridging the scientific and legal disciplines. For example, the NCFS found language such as “reasonable scientific certainty” to be meaningless and recommended that it not be used in court because it gives the false impression of scientific rigor.

Even more important, the NCFS recommended that all forensic techniques should be independently validated before being used in criminal investigations. Some of them have been, but too many have not. Bite-mark evidence is one example: despite lacking any scientific foundation, it is, incredibly, still being admitted into the courts. Last year the President's Council of Advisors on Science and Technology flagged firearms identification and latent fingerprint and footwear analyses as also unscientific.

Medical therapies, airplanes and electrical devices are tested by independent entities before they can be used routinely: the public demands that this be done and takes for granted that it has occurred. The public has the right to expect the same of forensic techniques, given the substantial consequences of the “evidence” produced in court. It must reflect “the truth, the whole truth and nothing but the truth.”
The DOJ now proposes to improve forensic science by moving its oversight and development to an office within the department. This is precisely the opposite of what was recommended by the National Research Council report and the NCFS. The DOJ is home to many dedicated public servants, including scientists whose passion for justice is unquestioned. But the department is not a scientific body, and it is difficult to see how forensic science can become a true science in such an environment. Science flourishes when it is free and independent; only then can the tools and technology that it creates be truly reliable.

Proclaiming evidence to be scientific does not make it so. Given this state of affairs, we are bewildered by the decision to end the NCFS. Questions about the validity of forensic science will not go away, and failure to address them will lead to further convictions of innocent people. For our society, the stakes don't get much higher.

*Arturo Casadevall, Johns Hopkins Bloomberg School of Public Health; Suzanne Bell, West Virginia University; S. James Gates, Jr., University of Maryland; Thomas D. Albright, Salk Institute for Biological Studies; M. Bonner Denton, University of Arizona.