The Sound Of Settled Science

When I was about 12, I read a book on “forensic science”, and for a time considered it as one of my career options. Little did I know, the field is more credentialist guesswork than it is solid science.

New research highlights the importance of careful application of high-tech forensic science to avoid wrongful convictions. The study was published on June 10 in the Proceedings of the National Academy of Sciences.

In the study, which has implications for a wide range of forensic examinations that rely on “vast databases and efficient algorithms,” researchers discovered that the odds of a false match significantly increase when examiners make millions of comparisons in a quest to match wires found at a crime scene with the tools allegedly used to cut them.

The rate of mistaken identifications could be as high as one in 10 or more, concluded the researchers, who are affiliated with the Center for Statistics and Applications in Forensic Evidence (CSAFE), based in Ames, Iowa.

Flashback: Bite marks, blood-splatter patterns, ballistics, and hair, fiber and handwriting analysis sound compelling in the courtroom, but much of the “science” behind forensic science rests on surprisingly shaky foundations.

4 Replies to “The Sound Of Settled Science”

  1. “….but much of the “science” behind forensic science rests on surprisingly shaky foundations. ”

    It REALLY gets interesting in courts, especially “Coroner’s Courts” when there is the distinct possibility of “police evidence tampering”.

    As the Romans might say:

    “Quis custodiet ipsos custodes”

  2. “….but much of the “science” behind forensic science rests on surprisingly shaky foundations. ”

    It REALLY gets interesting in courts, especially “Coroner’s Courts” when there is the distinct possibility of “police evidence tampering”.

    As the Romans might say:

    “Quis custodiet ipsos custodes”

  3. Unless you have a “tool” that wear pattern is absolutely unique, then any evidence claiming that any specific tool was used to cut a specific piece of wire is unlikely at best, as a lot of modern tool steel suffers from microdeformations in the process of cutting wire, especially if the copper has been work hardened.

  4. I recall seeing the reports that the entire fields of blood spatter and hair/fiber analysis had been shown to be no better than chance, statistically. I know that with fingerprints the issue is that many database matches rely on too few points of similarity, driving the odds of false matches up signficantly. And there are many reports of independent tests of DNA labs showing labs returning as many as 30% false matches from a batch of samples known to be unique, because of sloppy lab work.

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