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Analysis of Bank Dye Evidence and the Challenges of Daubert Hearings

NCJ Number
Pamela C. Reynolds
Date Published
January 2008
5 pages
This article explains how the analysis of bank dye-pack evidence can meet the challenges of a "Daubert" hearing.
In Daubert v. Merrell Dow Pharmaceuticals (1993), the U.S. Supreme Court's ruling made judges responsible for evaluating scientific testimony in order to determine whether it is both relevant and reliable for the case at issue. The Daubert case provides a set of guidelines that can be used to assist a judge in determining the reliability of the scientific technique being presented. The guidelines focus on whether the method can be tested, the known or potential error rate, whether there are standards for controlling the technique, whether the technique is generally accepted in the scientific community, and whether it has been subjected to peer review/publication. This article explains how each of these guidelines can be met under the FBI Laboratory's method of analyzing bank dye-pack evidence. Regarding the testing of the method, the analysis of bank dye-pack evidence should be done under the guidance of a validated standard operating procedure that details the materials and processes that will produce a given result. When procedures are validated, they are subjected to various testing in order to determine whether the technique is reliable and reproducible, as well as the detection limits for a particular chemical. Regarding known or potential error rate, an error rate determined by means of repetitive blind studies has not been established for bank dye-pack evidence analysis; however, conclusions regarding the presence of bank dye-pack chemicals rely on the results of multiple tests; the use of positive and negative controls ensures reliable results are obtained. The techniques for analyzing bank dye-pack chemicals and the techniques used for analysis have been published in a variety of literature.