Junk science and injustice: How flawed forensics trap the innocent

This is how the book “Junk Science and the American Criminal Justice System” by M. Chris Fabricant begins. Fabricant is the Director of Strategic Litigation at the Innocence Project.

Founded in 1992, its mission is to free innocent people from prison, prevent wrongful convictions, and create compassionate and just systems for all. “No year I spent as a public defender prepared me for this…But now I had a client who believed I could open the prison doors with a wave of a magic wand. It was terrifying,” wrote Fabricant in the book.

The American criminal justice system

What is junk science? Junk science is a term used to describe theories or methods that are presented as scientifically valid, despite lacking adequate research or evidence to substantiate them.

After his initial meeting with Steven Mark Chaney, Fabricant found himself in his rental car, parked outside the Huntsville prison.

As he reflected on the extraordinary visit, he began jotting down notes, realizing the potential for a broader narrative. His thoughts turned to his experiences with the Innocence Project and the critical issue at hand: how junk science had led to the unjust imprisonment of individuals like Chaney. This moment would serve as the catalyst for exploring the far-reaching consequences of flawed forensic practices in the American criminal justice system.

The first case is the story of Chaney, interwoven throughout the book. He was sentenced to life in prison for a murder he did not commit. “He was my first client at the Innocence Project and became a true friend. It is a very personal story and I think it shows the human cost of junk science and wrongful convictions. Not just for Mr. Chaney but for his entire family,” Fabricant told Interesting Engineering.

Chaney was released from prison in October 2015 after a court overturned his 1987 murder conviction due to discredited bite mark testimony.

The chapter he considers crucial for today’s society is “Executing the Innocent.” “Any honest reading of that chapter shows that we have executed innocent people in this country. The death penalty is barbarism and I hope it causes doubt among supporters of this outrageous practice,” says Fabricant.

According to available data since 1973, at least 200 people in the US who were wrongly convicted and sentenced to death have been exonerated. Reflecting a shift in public opinion, a 2019 Gallup poll revealed a shift in public opinion, with 60 percent of voters preferring alternatives to the death penalty for murder.

Gallup began asking the question in 1985, and for the first time, a majority of Americans said life in prison was a better approach to punishing murder. An estimated four percent of those sentenced to death are innocent, underscoring the ongoing risks of wrongful convictions.

Real-life examples of wrongful convictions

Sandra Hemme holds the record for the longest wrongful imprisonment of a woman in the US, according to her legal team at the Innocence Project. After serving 43 years for a murder she didn’t commit, Hemme was released in July 2024, when her conviction was overturned.

Curtis Edward McCarty was freed in 2007 after spending 21 years in prison, including 19 years on death row, for a 1982 murder he didn’t commit. As explained, he was convicted twice and sentenced to death three times based on prosecutorial misconduct and testimony from forensic analyst Joyce Gilchrist.

Roy Brown was convicted in 1992 for the murder of Sabina Kulakowski based on bite mark evidence. ABFO-certified diplomat Dr. Edward Mofson claimed matched Brown’s teeth. He was acquitted in January 2007 after DNA testing proved his innocence, having spent 15 years in prison.

Calvin Washington was wrongfully convicted in 1987 after a woman was found murdered in Waco, Texas. Though forensic evidence initially linked him to the crime, DNA testing later revealed that the blood on his shirt didn’t belong to the victim.

The real threat: Being wrongfully convicted

What are the biggest threats to forensic science today, and specifically, are there still people at risk of being wrongfully convicted?

“Yes, the threat to the innocent is real. More broadly, almost all forensic sciences rely heavily on human interpretation of data, and there is still no effort to mitigate the harmful effects of cognitive bias. When experts are exposed to irrelevant case information, our cases and scientific studies show time and again that this information leads to erroneous conclusions,” Fabricant explained.

As he noted, scientists can have a real impact on the justice system in ways that have yet to be realized because forensics is a completely separate field, leading to many of the problems he discussed in the book.

“Good science is how humanity understands the world around us; bad science is how we destroy the world around us. Most of us are not prepared to independently assess the validity of scientific information, so we must be vigilant about the credibility of sources. Failure to vet sources leads to bad science—in forensics, climate change skeptics, vaccine skeptics, etc.” he said.

He thinks wrongful convictions caused by bad science are an important story that can motivate the scientific community to engage more with the justice system, which will help improve scientific research.

One of the largest forensic scandals in US history

While individual cases highlight the impact of junk science, systemic issues can have even wider-reaching consequences.

Annie Dookhan was convicted of falsifying evidence while working at the Massachusetts Department of Public Health Drug Abuse lab. Her actions potentially affected up to 34,000 criminal cases.

Dookhan’s misconduct, which included tampering with drug samples and fabricating test results, led to one of the largest forensic scandals in US history. The fallout from her actions resulted in numerous convictions being overturned and a significant strain on the Massachusetts judicial system.

Autopsy of a crime lab

In his book Autopsy of a Crime Lab, Brandon Garrett, a law professor at the Duke University School of Law, describes one of the most important real cases in the history of fingerprint work—the case of Brandon Mayfield.

“The FBI’s errors in linking his fingerprint to a latent print left at the scene of a bombing in Madrid helped to illuminate all the ways fingerprint experts can be wrong. Fingerprint experts previously claimed to be infallible if properly trained, and judges accepted these claims. The Mayfield case began bringing exaggerated forensics down to reality,” said Garrett.

His book, like Junk Science by C. Fabricant, is for the US and the rest of the world.

When asked if he thinks there is a serious need for an autopsy of forensic sciences globally, he said: “The same types of forensic evidence are used worldwide, and unfortunately, worldwide, crime labs are often not regulated in the way clinical labs are. We would never allow clinical labs to conduct tests that are not scientifically validated or to employ analysts who are not carefully tested for proficiency as part of standard quality controls. Somehow, in criminal cases, quality controls are considered less important. The same factors, like the lack of standards, lack of statistical validation, and cognitive bias, affect traditional forensics worldwide. And wrongful convictions have occurred in high-profile cases worldwide.”

We have learned a lot about what can go wrong

As Garrett explains, scientific research has, in many ways, benefited the criminal justice system. “DNA tests can now be used in some cases to provide evidence of guilt or innocence. We now know how to test eyewitness memory more accurately. Cases of false confessions are far better understood. Thanks to the important work of the broader scientific community, we are much more aware of the limitations of many types of traditionally accepted forensic evidence. We have learned a lot about what can go wrong.”

He added that countries worldwide have begun to improve how criminal investigations are conducted. They have also adopted new rules that make it easier for people to challenge convictions based on new evidence of innocence. However, he concluded although some countries have less burdened crime labs, the lack of standards, quality controls, and basic research is a global problem.

The importance of the National Institute of Justice

“As director of NIJ, it is my priority to support rigorous and inclusive research that informs our efforts to promote safer communities and a more equitable justice system. That means that researchers should take the time to consult with and learn from, those who are closest to the issue or problem they are studying,” wrote Nancy La Vigne, director of the National Institute of Justice.

She told Interesting Engineering that one of NIJ’s main roles was to motivate the scientific community. They do that by providing opportunities to apply for and receive research grants that improve science on all topics, specifically research on evidence, technologies, and methodologies related to wrongful convictions.

“NIJ has awarded millions of dollars in grants for forensic sciences that have developed new fingerprint recognition technologies and DNA identification that have had a huge impact on the ability to identify factors that lead to wrongful convictions and provide lawyers with evidence that shows a conviction was indeed wrongful,” said La Vigne.

Science needs to be done right

“We know that science can tell us what works and what doesn’t; without that knowledge, we are essentially guessing. But science needs to be done right. As I have said many times: numbers plus narratives; that’s when research becomes truly impactful,” said La Vigne.

Science plays a crucial role in unraveling the complexities of wrongful convictions and guiding our approach to rehabilitation, both during incarceration and upon reintegration into society. By leveraging scientific insights, we can develop more effective strategies to support exonerees throughout their journey, from prison to community life.

“Science can also help understand the stressors faced by both incarcerated individuals and the officers responsible for their care. Addressing these stressors can lead to safer environments that are more conducive to rehabilitation and keep officers in the profession,” concluded La Vigne.

The intersection of science and criminal justice presents both challenges and opportunities.

Wrongful convictions highlight the devastating consequences of flawed forensic practices, while advancements in technology and increased scrutiny offer hope for improvement.

Moving forward, collaboration between forensic experts, legal professionals, and policymakers is crucial. By upholding rigorous scientific standards and fostering a culture of continuous learning, we can work towards a more accurate and just criminal justice system. The stories of those wrongfully convicted remind us of the stakes involved and the ongoing need for vigilance in questioning established practices.

As we progress, integrating sound science with compassionate justice will be key to preventing future injustices and ensuring our system truly serves truth and justice.