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The Problem of “Sci-enough” A Blog by Warren Bull
In October of 2005 comedian and social commentator, Stephen Colbert introduced the word “truthiness” on The Colbert Report on Comedy Central. He said, “truthiness is the belief in what you feel to be true rather than what the facts will support.” A similar word, perhaps “sci-enough” could be coined to describe methods used in court that appear to be based on science, but lack the reliability and validity to qualify as scientific.
It would be fantastic if such hope equaled accuracy. But courts have a long history of relying on techniques that sound believable but have not been tested. Upon testing, they fail.
For example https://www.propublica.org/article/911-call-analysis-fbi-police-courts
Tracy Harpster, a deputy police chief from suburban Dayton, Ohio, was hunting for praise. He had a business to promote: a miracle method to determine when 911 callers are actually guilty of the crimes they are reporting. "I know what a guilty father, mother or boyfriend sounds like," he once said. Harpster tells police and prosecutors around the country that they can do the same. Such linguistic detection is possible, he claims, if you know how to analyze callers' speech patterns -- their tone of voice, their pauses, their word choice, and even their grammar. Stripped of its context, a misplaced word as innocuous as "hi" or "please" or "somebody" can reveal a murderer on the phone. So far, researchers who have tried to corroborate Harpster's claims have failed. The experts most familiar with his work warn that it shouldn't be used to lock people up. Prosecutors know it's junk science too. But that hasn't stopped some from promoting his methods and even deploying 911 call analysis in court to win convictions.
An ongoing review of the Federal Bureau of Investigation's (FBI's) microscopic hair comparisons, in which forensic scientists look for distinguishing features such as the thickness, texture, and pigment in a hair strand, has revealed erroneous statements in more than 90% of cases before 2000 in which FBI examiners gave testimony.
The same article cites the case of Ray Krone.
Ray Krone was convicted of murder after prosecutors used bite marks on the victim's neck and breast to link Krone to the crime; he served 10 years in prison before DNA evidence showed that he was innocent.
Tire tracks and shoe prints and other measures based on the wear of patterns on the items reviewed can be helpful in a limited, but important way. They can conclusively yield results that a particular item was not the one that left tracks in the sand or mud near a crime scene. They cannot indicate more than that an item could have left marks consistent with what was found.
Latent fingerprints were examined in a series of tests. Many problems were noted in detecting and capturing the prints. In addition, it was clear that inexperienced evaluators were prone to high error rates. Even with the most experienced evaluators examining the best latent prints, the highest error rate was 1%. Although that sounds relatively high, for an accused person, the odds are far from reassuring. Any factors making the interpretation more difficult increased the error rate.
Another set of problems in how statistics are understood by both jurors and judicial officials. The average person can confuse the difference between one chance in a thousand and one chance in one hundred thousand. The practice of statisticians giving a range of numbers as showing the probabilities only confuses people even more.
Completely honest and well-intentioned investigators can rely on flawed investigatory methods.
Juries and judges can be influenced by the appearance of accuracy that is illusory.
Most worrisome to me is that new baseless and untested flimflams continue to appear.
That we unintentionally allow junk science into our courts is terrible.
That some knowing it is junk science still use it is disgusting. It should be a crime punishable by whatever unjustified sentence an innocent person had to serve.
I'm over "low, moderate, or high" risk statistics.
Interesting. Several years ago I was attended a presentation by the Innocence Project. It was eye-opening to discover how many convictions were later overturned based on faulty science.
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