On Junk Science, Pop Forensics and Crime Fiction

On the morning of October 12, 2017, a packed crowd in the Grand Centre Ballroom of the Sheraton Centre Toronto hotel stared politely at the grisly slide. It was the view from the dashboard of a taxi towards the front seat, soaked in blood, and the back seat, which had fared little better. The rapt audience listened as a detective from the Toronto Police Forensic Identification Services explained that the passenger had slit the driver’s throat before dashing out of the car. But he had left behind a footprint. And this detective had matched it. His lecture, after all, was on Forensic Footprints—a talk on “footprints that led to solved crimes,” and it was the opening lecture at Boucheron, packed with authors and fans of crime fiction looking for their next twist.

“But what about what we don’t know?” I asked, when the detective took questions. “Bite mark pathology has been debunked, spatter pattern has been questioned—are you ever less than sure you have gotten it right?” The lecturer assured me that his methods were rigorous, that any critique I had heard of spatter pattern analysis was spurious, and that forensic pattern analysis was the most reliable way to solve crimes.

The National Academy of Science disagrees. As long ago as 2009, an NAS panel issued a paper finding that “No forensic method has been rigorously shown to have the capacity to consistently, and with a high degree of certainty, demonstrate a connection between evidence and a specific individual or source.” The NAS panel did not critique merely novel practices such as bite mark evidence and spatter pattern analysis, but found that even humdrum pattern analysis including fingerprints, shell casings, shoe prints, and tire marks failed to meet basic scientific standards.

Journalists and lawyers have been exposing junk science for over a decade now, leading to a string of high-profile exonerations. Based on a partial fingerprint and ejector parts on a bullet casing, Bill Macumber was sentenced to life in prison in 1975 for a murder that another man had confessed to before being killed in prison the year before. He was only released 37 years later as lawyers mounted a challenge to the evidence. Louis Taylor, convicted of setting the Pioneer Hotel fire in Tucson when he was sixteen years old based on a forensic report that concluded that the fire was an arson and the arsonist was black, was released after 42 years when a review of the evidence suggested the fire had been accidentally started. Radley Balko, and Tucker Carrington dove deep into the failings of bite mark evidence in The Cadaver King and the Country Dentist, the story of the exoneration of Levon Brooks and Kennedy Brewer. And just this year, Pamela Colloff, who has reported on multiple wrongful convictions in Texas, exposed the scandal behind the conviction of Joe Bryan, which relied almost entirely on a few specks of blood on the lens of a flashlight recovered away from the crime scene.

The courts are only just beginning to catch on that they have been bamboozled for decades. Last year, Professor Paul Giannelli reviewed dozens of court cases that admitted evidence based on four “discredited techniques” including bite mark analysis, microscopic hair comparisons, arson evidence, and bullet lead analysis, and two techniques that have been “misleadingly presented’ including firearms/toolmark identification and fingerprint examinations.

It is becoming clearer every day that the scientific techniques used to solve crimes are mostly garbage. Junk science doesn’t just lead to wrongful convictions—it contributes to the already-enormous racial disparity in wrongful convictions in this country. Skepticism towards pattern evidence is not just for scientists and lawyers, but for anyone interested in reducing racism in our criminal justice system. Refreshingly, just this month a jury refused to convict a black 22-year old of the notorious “Queens jogger” murder despite the fact that his DNA was found at the scene. He had been interrogated for twelve hours before producing a confession that one expert said “seems like a narrative that may have been fed to him,” and his DNA was not the only sample found near the body, which had been discovered long after the murder.

But even as juries and judges begin to recognize the shortcomings of pattern evidence, some continue to laud the practice. The New York Times recently ran a story lionizing the use of ballistics evidence. To get a sense of the article’s scientific rigor, four days later the paper had to run a correction because it “misidentified an object” in a photo caption—as the paper admitted, the object “was a bullet, not a cartridge case.”

But nowhere is discredited science more alive than in crime fiction. Last year, I had the honor to serve as a judge for the Edgar Awards in the paperback original category. I was exposed to a slew of great new authors. Anna Mazzola, who wrote the winning book, The Unseeing, is a criminal defense lawyer who brought a critical view of evidence to an historical novel about a possible wrongful conviction. Jock Serong’s The Rules of Backyard Cricket is a terrific story of brotherly rivalry that evolves into crime almost accidentally. And Kanae Minato’s Penance is an extraordinary telling of four women haunted by a crime they witnessed in childhood. These books, and the other finalists, were filled with surprises and twists grounded in human psychology, not whether a fingerprint or a bullet magically solved a crime.

But the finalists were six books among hundreds. And many of the other entries relied on forensic magic. There was the hair sent to a DNA lab for results in 24 hours (only in the most fortunate cases can DNA be extracted from hair at all, and labs are perpetually overburdened). There was the arson examiner drawing conclusions from the stumps of a burnt house. And there were spatter patterns, fingerprints, tire tracks, and bullet casings. Reliance on these methods has led to shattering consequences for the innocent, most of them young men of color. I am glad to say that I didn’t read a book that was solved through bite mark evidence. That is some progress.

More than just relying on bad science, though, turning a plot based on pattern evidence can descend into bad storytelling. Our age is complex. Solutions are rare. And stories that reflect that complexity will seem more true. Crime may be down, but most crimes still don’t get solved—the clearance rate for major index crimes for the NYPD last quarter was only 33%. Stories that reflect this reality are in turn more compelling. Julia Dahl’s Conviction shows a district attorney’s office in all its unkempt reality, down to the lost bankers’ boxes of evidence. Richard Price’s Lush Life reveals the killer right away and tells the story mainly of the botched arrest of the wrong suspect.

There are, of course, huge questions that can still be investigated in the intersection of crime fiction and science. Can law enforcement obtain the data from a smart speaker? What happens when facial recognition software mistakenly accuses someone of a crime because it saw her picture on the side of a bus? There is plenty of mystery in the science we have, without having to rely on the science that has led to so much real-life injustice.

I have wondered many times since that ballroom in Toronto how many attendees have since decided to include a bloody footprint in their next book. And of those, I wondered how many listened closely as the detective described how the taxi murder had been solved. Sure, the footprint in the back of the car matched the shoe of the person they arrested. But that was all gravy. After all, the whole ride, including the murder, had been recorded by the taxi’s onboard video.