It’s truly scary how many ugly stories of sloppy forensics are emerging under the white hot light of real, peer-based scientific scrutiny. A lot of the credit for the movement toward hyper-scrutiny has to go to Barry Scheck’s Innocence Project (as of this writing, they are up to 163 exonerations), whose group is probably single-handedly responsible for setting the new national tone of skepticism. Death penalty executions are down 50% this year and 12 states have abandoned the death penalty altogether as news continues to pour in about the victims of junk science. And while death penalty proponents continue to whine about the lack of attention being directed at the real victims of crime, they don’t seem to grasp the idea that convicting innocent men not only deprives these victims of any real justice, but also leaves the genuine killers out on the street to continue killing. Duh. It’s hard to imagine a better cause for both sides to unite around. But as long as people are making money and building reputations selling junk science to a public hungry for retribution and quick solutions, expect to see resistance to any effective efforts to clean things up.

And so it’s no surprise to see lines being drawn over new attacks against one of the most highly regarded and frequently utilized tools in the toolbox of the forensic lab. It’s called Gun Shot Residue analysis, or GSR. This technique is utilized to identify the sometimes microscopic evidence of residue left after a gun has been fired, and thereby associate an individual with a gun or crime scene. The only problem is, there aren’t sufficient standards on how to apply these techniques, and the resulting subjectivity opens up major potential for error and abuse.

GSR suffers from several significant problems. One is the idea that supposedly “unique” particles used to identify gunshot residue on a suspect are not so unique after all. It turns out that some of these so-called “unique” particles can be transferred to a person in completely innocent ways. A recent issue of Forensic Science International reports the odd result that automobile mechanics are particularly at risk because one of the metals found in brake linings is considered one of these “unique” particles indicating the presence of gunshot residue.

Another problem is simply crime scene contamination, and here GSR is particularly vulnerable. A recent study (once again, in Forensic Science International) found that a non shooter could be contaminated with GSR particles without ever going near a firearm, and the Los Angeles County Coroner’s office found in a study of its own that police cars were a prominent source of contamination. In the L.A. case, they found that 45 of 50 samples taken from the backseat of police cars contained particles “unique” to GSR and consistent with highly specific GSR particles. How many innocent people have been placed at a shooting scene simply because they rode in the backseat of a police car teeming with GSR particle contamination? /shrug

The latest issue of New Scientist.com (one of my daily blog stops) reports on the new questions challenging traditional GSR findings. In an article entitled Why we cannot rely on firearm forensics, New Scientist.com relates the story of a man serving a life sentence based on questionable GSR findings. What’s even more interesting is the report that a recent FBI Symposium discussed ways of improving standards and techniques (curiously, the FBI would not comment on this) and is preparing a paper to be published with new recommendations on GSR procedures. Tacit admission that current “science” isn’t really science after all.

RP

This entry was posted on Friday, November 25th, 2005 at 8:22 am and is filed under News, Junk Science. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.