I am just now getting around to watching an episode of Frontline, the PBS documentary, titled "The Real CSI." The episode originally aired in April 2012 and was recently re-aired. From the link, I believe it is now viewable online, though I can't guarantee how long it will be available if at all to you.
If I had my way, though, this would be required viewing for all prosecutors, defense attorneys, judges, CSI wannabes, and all prospective jurors. So basically all citizens.
Forensic sciences aren't what they're portrayed to be on t.v. They aren't what people on message boards think they are. More importantly, they frankly aren't how they're portrayed in court. Much of what passes for science in courtrooms is junk promoted by people who don't know what they're talking about. But they have degrees and lots of experience and they use big words, so their views are accepted by judges, prosecutors, and juries who don't have the expertise to see through the claims.
Prosecutors always bemoan "The CSI Effect," complaining that they can't get convictions without presenting scientific evidence. I think the real CSI effect, though, is rather the opposite: when the prosecution does put on scientific evidence, be it fingerprints or dog scent line-ups or bite marks or whatever, juries accept it.
On this show, one of the nation's most renowned fingerprint experts blew the reporter's mind by calling the act of declaring a fingerprint match to be a "leap of faith." The very premise of fingerprint analysis is based on an unproven (indeed a false) premise: that all fingerprints are totally unique. Poor Brandon Mayfield, the Portland attorney who was wrongly accused in the Madrid train bombings of 2004, exposed the untruth of that premise. It doesn't appear too many established FBI fingerprint examiners are too interested in figuring out if his case of mistaken fingerprint identity is an anomaly or the tip of the iceberg.
Science is complicated and something most of us don't think about much after we get done with the science requirements for graduating high school. I fear that most of us tend to defer to the "experts" too easily, having forgotten that a key requirement for any consideration of scientific claims is skepticism. Science can be a tremendous tool, when done correctly. But when it's bad... Well, it's like the girl with the curl: when it is good, it is very, very good, but when it is bad, it sends innocent people to death row.
So watch this episode of Frontline or read articles critical of forensic sciences. If you get called for a jury before doing either of those, though, here are some thoughts:
Be wary of experts who base their conclusions on their years of experience, not rigorous application of the scientific method to repeatable testing.
Be wary of experts who claim infallibility or no error rate.
Be wary of DNA analysts who declare 100% matches on partial DNA profiles or fingerprint examiners who declare matches on a small number of print points. Be very wary of the examiners who aren't open to considering the possibility that there are more DNA and fingerprint similarities than we had previously realized.
Microscopic hair analysis is bunk, so for sure be wary of anyone who says otherwise.
I know I've said all this stuff before elsewhere and have begged people to be more critical toward forensic sciences. But it needs to be repeated again and again as long as bad science is clogging our courts and sending people to prison.