Reviews | An Innocence Project lawyer’s book shows where science collides with the law

(Washington Post illustration; iStock images)
(Washington Post illustration; iStock images)

One of the most difficult problems in the criminal justice system is how to assess expert testimony. Who can offer expertise to juries, and how can courts ensure that this expertise is reliable? The exoneration files are full of quack pundits who have done untold damage, both by sending the innocent to prison and allowing the guilty to be set free.

Mr. Chris Fabrication, Director of Strategic Litigation for the Innocence Project, has been on the front lines of these fights for more than a decade. In his fierce and captivating new book, “Junk Science and the American Criminal Justice System“, Fabrique recounts the battles he and his colleagues fought to unravel a century of fraudulent experts and the bad court rulings that allowed them to thrive.

The age of the dodgy forensic scientist began with the rise of early 20th century progressivism, a movement that commendably sought to eradicate political corruption and replace it with science and expertise. But the progressive penchant for expertise could sometimes turn into charlatanism – often mixed with racism. Perhaps the best example is Sir Francis Galton, a Victorian-era polymath often cited as the father of fingerprint identification. Galton was a mathematician, a scientist, and something of a celebrity. But he was also a believer in phrenology and eugenics (he actually coined the term) and supported the involuntary sterilization of groups he considered undesirable.

Judges have long been the guardians of expertise. But judges are trained in law, not science, and they are two very different disciplines with almost contradictory goals and methods of analysis. The law favors consistency and reliability; science is constantly evolving based on new evidence and new discoveries.

For a long time, the two fields did not intersect much. The criminal justice system has developed the field of forensic pathology, a series of disciplines covered in the veneer of science but mostly not subject to the rigors of the scientific method, such as double-blind testing or peer review. peers. For decades, judges have allowed trials to be polluted with pseudoscientific testimony in the fields like arsonhair and carpet fiber matching, forensics and ballistic.

The credibility of some forensic disciplines took a hit in the 1990s when DNA testing – real science – began to show that some prisoners those experts had found undeniably guilty were, in fact, innocent. Maker’s book picks up about 20 years after DNA testing became commonplace, as courts continue to grapple with this fundamental square-peg/round-hole problem: how to reconcile science and law.

The book focuses on three of Maker’s cases involving bite mark analysis, a field that burst into popular culture during the Ted Bundy trials in the 1970s and reached its peak in the 1990s. Bite mark analysis relies on two unproven premises: the first is that each person’s teeth leave a unique bite mark. The second is that human skin is able to register and store these marks in a way that allows them to be matched to a specific person.

The manufacturer documents how People against Marx, a murky 1975 California Court of Appeals decision with an unusual set of facts, set in motion a formidable body of law establishing bite mark analysis as a court-approved expertise. Paradoxically, in this case, the court itself recognized that the correspondence of the bite marks is not Science. (The judges instead ruled that in this specific case, the bite mark evidence was common sense, allowing them to skip a scientific review.) This ruling has since become the urtext for a cascade of rulings authorizing a variety of scientifically dubious disciplines. The resulting case law has been the legal equivalent of the childhood game of “telephone”. A little after marx, other court decisions have cited him, misrepresenting his decision to allow a new application of bite mark analysis and similar techniques. Another wave of judgments was then cited, introducing still new applications and new methods of analysis. Each new citation was a misapplication of the original ruling, each expanded the use of questionable techniques, and each citation only further cemented the already flawed original ruling as canon.

In the 1990s, DNA testing began excuse people who had been accused of crimes by bite mark experts, a growing group of about two dozen today. These exemptions aroused the interest of scientists, who then began to scrutinize the failing discipline. In recent years, many peer-reviewed studiesscientific bodies and proficiency testing have shown or concluded that these fundamentals of bite mark analysis are just not true.

Yet, as in other refuted areas of forensics, the courts have stubbornly refused to catch up. Last February, an Alabama judge confirmed a murder conviction was won primarily due to bite testimony, despite the fact that the dentist who testified at trial recanted. A month later, a Michigan man was convicted of child abuse in part because expert witnesses for the state claimed to have found bite marks on the child that could only have been left by the man’s chipped tooth. While this sort of theory might seem plausible to an audience conditioned by CSI reruns, the legal record is littered with convictions of so-called oddly toothed men who later turned out to be innocent.

The most damning thing here is not the exonerations, but the fact that the courts have failed to course correct after learning about them. The manufacturer emphasizes that in at least three states – Wisconsin, Massachusetts and Mississippi – the compelling precedent establishing the bite mark analysis as credible ended up upholding the conviction of a person who was later found to be innocent. That is, in the very case that still permits the use of bite mark analysis in these states – and to which lower courts must defer today – the bite mark analyst got it wrong .

Jon J. Epps