The Past and Future of FORENSIC SCIENCE and the COURTS
Saks, Michael J., Judicature
Whatever tests of admissibility of expert testimony might formally have existed in various jurisdictions at various periods over the past centuryor so, they were applied infrequently to government proffers of forensic science. Moreover, several of what might be regarded as the vintage offerings of the forensic sciences - notably handwriting and fingerprint id e ? ti fi cat i on - were widely admitted before 1923, when Frye v. United States1 was decided. But - as if to underscore the point that careful screening of expert testimony was not applied with the same vigor to government proffers in criminal cases - on the very same day that Judge Van Orsdel held defense-proffered polygraph testing to be inadmissible because it was a novel expertise thai had not yet crossed die line from "experimental" to "demonstrable,"and was not yet "generally accepted," the very same judge reviewed die novel technique of firearms identification - also untested, "experimental," not yet generally accepted, and had recently been found inadmissible by a prominent state supreme court* - and held that its admission by the trial court in Laney v. United Slates was proper.' In fact, in Laney, Judge Van Orsdel did not so much as mention Frye or any requirement of general acceptance.
The casual* acceptance by courts over the past century of whatever the government proffered in the name of scientific expert testimony is beginning to catch Lip with the law. A recent report" by the Committee on Identifying the Needs of the Forensic Science Community of die National Research Council spent over two years studying numerous of these subfields, looking especially for "scientific research to support the validity and reliability of existing forensic disciplines," and often found a knowledge base inadequate to justify the conclusions offered daily in American courts. "The bottom line is simple," concluded the Committee: "In a number of forensic science disciplines, forensic science professionals have yet to establish either the validity of their approach or the accuracy of dieir conclusions, and the courts have been utterly ineffective in addressing this problem."7
Once courts admitted extreme claims - identifying some person or object as die source of crime scene evidence "to the exclusion of all other persons or objects in the world," though undergirded only by plausible ideas and subjected to little or no systematic empirical testing - why bother to test? What could research accomplish? Rigorous testing was accompanied only by disincentives: time and resources taken away from casework, discoveries that witnesses were overstating some (if not many or most) of their conclusions, with consequent need to attenuate future testimonial claims, and embarrassment over past exaggerations. All of this could be avoided by doing nothing. Given courts' ready acceptance of anything the witnesses came to court to say, life could get no better than it already was."
The unraveling dial culminated in the NRC Report can be traced to diree events: one legal, one scientific, one mixed.4 First, the Supreme Court's decision in Dauberl v. Merrell Dow Pharmaceuticals'" changed the inquiry for admissibility to essentially the question scientists ask: What empirical evidence supports the validity of the expert's claims? This opened the way to challenges that forensic science had rarely if ever faced before. Numerous courts found themselves at the brink of excluding expert testimony diat had come to be viewed as nearly flawless. Although judges usually found ways to admit the evidence, doubts inevitability arose and were not dispelled."
Second, the advent of DNA typing provided a general model of how forensic identification could be accomplished: basing it on a sound theoretical foundation borrowed from normal science, developing an acceptable probabilistic model, and building a database of empirical data on which to base case-by-case probabilistic conclusions. …