Volume 34, Issue 6 (November 1989)
A Perspective on Probability and Physical Evidence
Evaluating the significance of physical evidence often requires a consideration of the probability of chance occurrence of the evidential properties and an appropriate target population. These are used to calculate the probability of duplication of the properties within the target population, which in turn is used to evaluate the significance of the evidence. The target population chosen for consideration by the expert witness generally cannot be the same as that used by investigators or a jury. This paper discusses the choice of an appropriate target population by the expert and offers a suggestion for aiding the jury in evaluating the expert's opinion with respect to other evidence in a case.