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A blog written for those whose interests more or less match mine.

A brief history of forensics and the perverse incentives that undermine the science

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Radley Balko has a very interesting Washington Post column today:

My Washington Post colleague Spencer Hsu continues his great reporting on the continuing crisis in the world of forensic science. Over the weekend,Hsu broke the story that Justice Department officials now concede that “an elite FBI forensic unit gave flawed testimony in almost all trials in which they offered evidence against criminal defendants over more than a two-decade period before 2000.”

This is far from the first such story. It isn’t even the first such story from the FBI’s crime lab, long considered one of the most elite labs in the world. In fact,  over the last several years there seems to be a new crime lab in crisis about once a month. A big part of the problem is misplaced incentives. A couple years ago I reported on a study which found that in many states, crime lab analysts are actually paid per conviction. [This is much like the idea of paying Quality Control inspectors based on the number of items that pass inspection. – LG] And few years before that study came out, one of its authors — Roger Kopple of Fairleigh Dickinson University — and I wrote a piece about how we could institute some meaningful reforms to get those incentives pointing in the right direction.

But Hsu’s story seems like a good opportunity to post a bit of a history of forensics that I wrote a few months ago. This was initially part of my four-part series on the use of bite mark evidence in the courts. We cut it because the series was already pretty long. But I think it provides some useful context for these alarming stories we’re seeing today.

A quick history of forensic science

In 1911, prosecutors for the state of Illinois won a murder conviction against Thomas Jennings. They did so by convincing a jury that Jennings’s fingerprint matched the fingerprint left on a freshly painted window sill at the house where the victim was killed. By that time, fingerprint matching had been used in Europe for a few decades. It had been introduced to U.S. law enforcement officials by Scotland Yard officials at the 1904 World’s Fair in St. Louis. The Illinois Supreme Court would later uphold Jennings’s conviction, ruling that “the [fingerpint] evidence in question does not come within the common experience of all men of common education in the ordinary walks of life.” Therefore, the justices found, “the court and jury were properly aided by witnesses of peculiar and specialized experience on this subject.”

It’s somewhat appropriate that modern forensics would have been introduced to America at that World’s Fair in St. Louis. The early 20th century saw a wave of  innovation, reform and social upheaval, along with some exciting new technology. Mass electrification was underway. The dawn of what would become the American Century saw landmark advances in science and discovery, and the 1904 exposition was an early and prescient celebration of American achievement, both heralding the advances that had already occurred and anticipating those to come.

But such celebrations of American exceptionalism could quickly bleed into chauvinism about American superiority, ugly demonstrations of alleged racial dominance and the championing of crank theories too easily passed off as science. Among the fair’s many exhibits, for example, were disturbing living dioramas of native “savages” collected from all over the globe —basically a human zoo. Paired with the exhibits celebrating America’s technological advances, the dioramas were intended to show that America was ascending due to a sort of evolutionary superiority. There were also exhibits on pseudo-sciences like phrenology and physiognomy, which posited that trained experts could make broad generalizations about intelligence, criminal proclivity and morality based on physical characteristics like skull size, skull shape and the sizes and relative ratio of body parts.

Perhaps the best example of how easily good science could quickly go terribly wrong was Sir Francis Galton, a Victorian-era statistician, mathematician and meteorologist who is also considered the father of modern fingerprint identification. Galton’s interest in fingerprints was inspired by his admiration of the work of Alphonse Bertillon, a Paris police officer who pioneered the use of anthropometry — taking and recording careful measurements of body parts for the purpose of identification. Bertillon’s methodology was sound, and it vastly improved identification of suspects and convicts and helped law enforcement officials identify repeat offenders. By the end of the 19th century, it had been adopted by police agencies across the U.S. and Europe. It was one of the first examples of scientific classification in law enforcement.

But Galton’s enthusiasm for anthropometry not only inspired his work on fingerprint analysis, he soon came to believe that certain physical traits were indicative and predictive of criminality, intelligence, virtue, morality and other traits. This belief that people of a certain nose size, skull shape, or skin tone were inherently more criminal, immoral, or less intelligent quickly took Galton to the ugly places one would expect it might. In his autobiography, he advocated for the forced sterilization of entire groups of people. “Stern compulsion ought to be exerted to prevent the free propagation of the stock of those who are seriously afflicted by lunacy, feeble-mindedness, habitual criminality, and pauperism,” he wrote. In fact, the father of modern fingerprint analysis not only became a champion of the ugly field we now know as eugenics, he actually coined the term.

 This embrace of science and charlatanism was also present in the Progressives, the ascendent political movement of the early 20th century. Progressive reformers saw themselves as champions of empiricism and intellectualism. They sought to replace the corruption, cronyism and patronage they saw in politics and public service with expertise, altruism and virtue. But the Progressives too could sometimes let their enthusiasm lead them astray. The desire to build a better society often included the advocacy of immigration controls, the sterilization of “undesirables” and policy prescriptions based on broad generalizations about entire racial and ethnic groups.

American police departments were often at the center of these debates. In his book “Popular Justice,” criminologist and historian Samuel Walker notes that in the early 20th century, policing in urban America  was largely controlled by political machines. A police officer was an appointed, patronage position. The Progressives sought to professionalize law enforcement by transforming it from a temporary perk into a career. The reforms went a long way to rid policing of corruption and patronage, but they also wanted police entrusted with more paternalistic responsibilities — basically, to enforce virtue on immigrant populations whom progressive leaders thought lacked morality, discipline and industriousness.

It’s within this movement toward professionalism that we see the birth of modern forensics. Pioneers of modern policing like Berkeley, Calif. Police Chief August Vollmer emphasized standardization, the adaptation of new technology and specialization with law enforcement agencies in areas like homicide investigation, narcotics investigation and vice units. Forensics was also an area of specialization. In fact, Volkmer is credited with inventing the crime lab.

The professionalism movement promoted a more analytical approach to fighting crime, but as with other segments of American society at the time, the rush to embrace new theories and new technologies also opened the door to charlatans, hucksters and frauds. U.S. courts were now faced with the challenge of how to distinguish expertise from artifice. “Peculiar and specialized experience” could be useful, as the Illinois Supreme Court put it in People v. Jennings, but that couldn’t be the only standard. Someone could have peculiar and specialized knowledge in Tarot card reading, for example, but it wouldn’t be appropriate to let that person testify in court.

 “The standard at the time was that if someone had specialized knowledge, and that knowledge seemed to be helpful to investigators, then the court would allow the testimony,” says Jonathan Koehler, a behavioral scientist and law professor at Northwestern University. “The problem was that there was no attempt to check the validity of what these witnesses were actually claiming.”

And the problem with that is that most forensic disciplines weren’t invented in labs, then subjected to peer review in scientific journals. Instead, most were invented by people in law enforcement, not in the quest for knowledge, but as an aide to help them solve crimes. Scientists within the same field have strong incentives to poke holes in others’ theories, to find flaws in a peer’s experiments. This isn’t the case in forensics. A fingerprint analyst testifying for the defense might disagree with a fingerprint analyst for the prosecution, but he isn’t going to call into question the premises on which the entire field of fingerprint analysis is based. He’d be undermining his own legitimacy. It was only after the onset of DNA testing, which did come from the world of science, that we began to understand just how profound these divergent incentives really are.

Twelve years after Jennings, the first federal appeals court took a first stab at setting some standards in expert testimony. . .

Continue reading.

Written by LeisureGuy

21 April 2015 at 10:19 am

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