The admissibility and evaluation of scientific evidence in court

Abstract

Increasing use is being made of various types of scientific evidence in court. The general requirement for the admissibility of such evidence is relevance. Although expert evidence is considered to be opinion evidence, it is admissible if it can assist the court to decide a fact in issue; provided that it is also reliable. In South Africa, the initial wide judicial discretion to either admit or exclude unconstitutionally obtained evidence, has developed into a more narrowly defined discretion under the final Constitution. Examples of scientific evidence, namely, DNA evidence, fingerprints, psychiatric evidence, bite-mark evidence and polygraph evidence are considered and problems inherent in the presentation of such evidence in courts in various jurisdictions are highlighted. An investigation of the presentation and evaluation of evidence in both the accusatorial and inquisitorial systems seems to indicate that the adversarial procedure has a marked influence on the evaluation of evidence