Admissibility of Scientific and Technical Evidence Today: Fallout from Daubert
Since the Daubert decision in 1993, most states in the United States have adopted the principles of the decision in whole or in part. The rest still use the Frye rule. There has also been interesting fallout from the Daubert decision. The mandate for having a demonstrable scientific basis for introducing novel scientific or technical techniques in court has caused the legal and forensic scientific communities to take a fresh look at forensic scientific disciplines that were heretofore assumed to be proper and correct from a scientific basis. For example, there have been some recent challenges to the admissibility of testimony by expert questioned document examiners where there is a definite conclusion of authorship of a handwritten document. The basis for the challenges is that there has been little or no demonstrated scientific research that proves that handwriting comparisons are valid techniques for establishing definite authorship. At least one case has had a challenge to morphological human hair com parisons. In this case, the forensic scientist was going to testify that the defendant was one of an indeterminate population of people that could have been the source of the hairs found at the crime (rape) scene. The judge excluded the evidence as being too speculative and not scientific enough for the jury to consider. There have also been some recent challenges to the validity of “matching” partial latent fingerprints with known prints of a suspect. As in the cases with handwriting comparisons, the issue is the scientific basis (or lack of it) for concluding that fingerprints are unique and can be matched reliably. There is little doubt that the courts will be dealing with additional issues of the sufficiency of the science that underlies scientific and technical methods, processes, and techniques. Recently, as a result of the findings in Daubert, the Congress changed some of the rules regarding the admissibility of novel scientific evidence. For example, language was added to FRE 702 at the end. The rule now reads:
Since Daubert was adjudicated, two other important cases were heard and went to the Supreme Court that refined Daubert. Kumho Tire, a case involving defective tires, put forth the principle that the admissibility requirements of Daubert extend beyond scientific evidence into the realm of technical and engineering cases.
The other case, General Electric v. Joiner, was concerned with fluids that keep elec trical transformers from overheating and the possible harm of these fluids. The judge was asked to determine the admissibility of testimony involving these fluids. The judge exercised his discretion as a “gatekeeper” under Daubert, to exclude the testimony. The Supreme Court ruled that this discretion fell within the judge’s discretion. These three cases (Daubert, Kumho Tire, and Joiner) have become known as the “Daubert Trilogy.” The National Academy of Sciences Forensic Science Committee also weighed in on these issues in its 2009 report. They stated that more research was needed to establish the validity of many types of scientific evidence in order to bolster conclusions of association reached by experts. The conclusions reached by the Committee were based, in part, on the outcome of the Daubert case.
