Yesterday I had two guest speakers from the WV Innocence Project come to class to talk about the work they do. For those not in the know, the Innocence Project is essentially a loosely-connected group of lawyers and legal advocates who review the cases of and advocate for factually-innocent prisoners. This bit of tortured language, factually innocent, is necessary because the only people the Innocence Project represents are people who they can indeed prove are innocent of the crime for which they're incarcerated. This makes their work, which often consists of a very long struggle to get the innocent person released, demonstrates a great deal about the problems with our criminal justice system. I find that students tend to take them more seriously, as they (like a lot of Americans) dismiss the idea of people being denied their constitutional rights during an investigation or trial as an actually meaningful defense (which has always confused me, because why have a constitution if we decide it's protections are really just cumbersome "technicalities?"). But no such argument here, as the people in question are empirically innocent (the vast majority proven so by DNA testing).
Although I'm pretty familiar with the work of the Innocence Project, I haven't devotedly followed their publications, and as such learned quite a bit from those two guests. But the most surprising to me was that of the 321 people exonerated by the Innocence Project, over half of them were originally convicted due to faulty conclusions drawn from forensic science.
Even more surprising was learning that of all the various forms of forensic analysis (hair analysis, fingerprints, bite marks, firearms analysis, tread and sole marks, etc.), pretty much the only valid and reliable one is DNA analysis. According to a massive study from the National Academy of Sciences, all other forms of not only lack any sort of national or conventional standards or training, but have also never been proven to be scientifically valid.
While the report goes into great detail about the relative validity of various forensics techniques, the general conclusion is that they're less on the level of DNA testing (pretty reliable) but instead much closer to the level of the polygraph (that is, may help aid an investigation, but nowhere near reliable and valid enough to rely on for a conviction).
As the fine folks from the WVIP did a good job explaining, these problems don't necessarily come from willful ignorance or intentional misconduct, but instead from the fact that our scientific understanding of most of these forms of investigation is still very much in its infancy. That, and we place a great deal of emphasis on precedent at pretty much every level of our cjs, and this is just always the way we've done things. Of course, the fact that it's no one's fault is small comfort to the wrongly convicted.
This adds yet another layer to my long-gestating argument that television police, courtroom, and prison dramas are not only terrible tv, but are actually harmful, as they present a world so unlike ours yet clearly many people believe them to be only slight exaggerations of reality, if at all. On tv, the plucky forensic scientist/detective/swimwear model can find a single hair and unravel an entire case. In reality, we can be fooled into thinking dog hair is evidence a human committed a crime...