The Body Farm/Oak Ridge National Lab

Although research has been done in some disciplines, there is a notable dearth of peer-reviewed, published studied establishing the scientific bases and validity of many forensic methods.

Often in criminal prosecutions and civil litigation, forensic evidence is offered to support conclusions about “individualization” (sometimes referred to as “matching” a specimen to a particular individual or other source) or about classification of the source of the specimen into one of several categories. With the exception of nuclear DNA analysis, however, no forensic method has been rigorously shown to have the capacity to consistently, and with a high degree of certainty, demonstrate a connection
between evidence and a specific individual or source. In terms of scientific basis, the analytically based disciplines generally hold a notable edge over disciplines based on expert interpretation. But there are important variations among the disciplines relying on expert interpretation. For example, there are more established protocols and available research for fingerprint analysis than for the analysis of bite marks. There also are significant variations within each discipline. For example, not all fingerprint evidence is equally good, because the true value of the evidence is determined by the quality of the latent fingerprint image.

Several articles, for example, have noted the lack of scientific validation of fingerprint identification methods.

…a trial judge must ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable.” The Court indicatedthat the subject of an expert’s testimony should be scientific knowledge, so that “evidentiary reliability will be based upon scientific validity.” The Court also emphasized that, in considering the admissibility of evidence, a trial judge should focus “solely” on the expert’s “principles and methodology,” and “not on the conclusions that they generate.” In sum, Daubert’s requirement that an expert’s testimony pertain to “scientific knowledge” established a standard of “evidentiary reliability.”

In explaining this evidentiary standard, the Daubert Court pointed to several factors that might be considered by a trial judge: (1) whether a theory or technique can be (and has been) tested; (2) whether the theory or technique has been subjected to peer review and publication; (3) the known or potential rate of error of a particular scientific technique; (4) the existence and maintenance of standards controlling the technique’s operation; and (5) a scientific technique’s degree of acceptance within a relevant scientific community.14 In the end, however, the Court emphasized that the inquiry under Rule 702 is “a flexible one.” The Court expressed confidence
in the adversarial system, noting that “[v]igorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof are the traditional and appropriate means of attacking shaky but admissible evidence.” The Supreme Court has made it clear that trial judges have great discretion in deciding on the admissibility of evidence under Rule 702, and that appeals from Daubert rulings are subject to a very narrow abuse-of-discretion standard of review. Most importantly,
in Kumho Tire Co., Ltd. v. Carmichael, the Court stated that “whether Daubert’s specific factors are, or are not, reasonable measures of reliability in a particular case is a matter that the law grants the trial judge broad latitude to determine.”