CSI Science a Myth?

According to this article in Popular Mechanics, the science behind the "bite marks, blood-splatter patterns, ballistics, and hair, fiber and handwriting analysis" sound compelling but have shakey scientific foundations, and there is very little body of scientific work to standardize anything.

"In recent years, legal experts have become deeply concerned about the accuracy of the “friction ridge analysis” central to fingerprint identification. Fingerprints are believed to be unique, but the process of matching prints has no statistically valid model."

"A subsection of tool-mark analysis, ballistics matching is predicated on the theory that when a bullet is fired, unique marks are left on the slug by the barrel of the gun. Consequently, two bullets fired from the same gun should bear the identical marks. Yet there are no accepted standards for what constitutes a match between bullets. Juries are left to trust expert witnesses. “‘I know it when I see it’ is often an acceptable response,"

"[Despite DNA's effectiveness] DNA constitutes less than 10 percent of the case load at U.S. crime labs."

I just finished a book called The Devil's Advocates: The Greatest Closing Arguments in Criminal Law History that surveys ten of the most important criminal cases in US history. It includes summations by John Adams, Clarence Darrow, and others. What struck me about these famous criminal cases tried so long ago was their sole reliance on witness testimony and the potential confession of the accused. It is comforting to know that the era of witness testimony in the halls of justice has been waning for years and the era of forensic science is ascendant.

It troubles me though to read something like that, demonstrating how little "science" has been done in the field of "forensic science." Of course there will be growing pains in any field. It took over 30 years from the discovery of the double helix to the conviction of a criminal based on DNA. I have even read articles that suggest the DNA system is not as foolproof as experts suggest (with its "one in 100 billion odds" theme).

What we end up with is a system predicated on shaky or faulty science, and thus the justice it dispenses becomes disputable and questionable. When we take away all the elements (witness testimony, forensic science, etc.)that have no foundation in stone we are left with little beyond logic. Even universal morality (people shouldn't murder) crumbles under the relativistic strain of morality present in our post-modern society. Thus, logic, conclusions derived from first principles, is the only thing left. Prosecutors and defense attorneys can bludgeon each others' witnesses and "forensic science" but they cannot pierce a tightly logical argument. This seems to be the last bastion of refuge amidst all the questions of validity concerning judicial evidence.