Vanderbilt Law Review

First Page



Modern scientific methods of fact-finding present evidentiary problems of admissibility which are grounded in reliability of the process, validity of the technique employed and desired policy objectives. In the final analysis, these three facets of the problem are all indivisibly interrelated since, in order to determine acceptable policy, scientific process and application of that process must inevitably be considered in the light of the concept of due process even though due process as such may not be posed affirmatively in any particular decision.' Moreover, it must be recognized that these factors will be present in varying degrees of intensity, dependent upon the facts and circumstances of a given situation. As to reliability of a scientific process, test or experiment, the proposition here advanced is that if the particular process, such as a lie detector test or a test to determine intoxication, is so unreliable as to have little or no probative value, the admission on behalf of the state of the results thereof in a criminal prosecution would violate due process; the same material could likewise be excluded by invoking the rule of immateriality. On the other hand, if the results of such tests are of probative value and favorable to the defendant, exclusion would violate due process; even though the reviewing court could confine its consideration to rules of evidence and find prejudicial error on the part of the trial court in excluding evidence material to the issues.

As to the validity of the technique employed, this phase of the problem can be viewed as being double-barrelled in nature. That is,"validity" may refer to the scientific validity of the technique utilized in conducting a test and may be assessed by looking to the qualifications of the expert and the observance of proper control procedures by such expert. On the other hand, the reference may be to the constitutional validity of the technique employed, which can be judged in'regard to the person subjected to the test and the manner in which his participation is secured. This participation may be voluntary or involuntary, and it is the purpose of this article to investigate the issues raised thereby, in the light of society's objectives under existing rules of evidence and relevant constitutional safeguards.