ISSN: 0022-1198
CODEN: JFSCA
Page Count: 6

How Many Samples from a Drug Seizure Need to Be Analyzed?
Coxon, A
Forensic Scientist, ESR,

Buckleton, JS
Forensic Scientist, ESR,

Coulson, SA
Forensic Scientist, ESR,

(Received 11 November 2000; accepted 15 February 2001)

Abstract

Recently Aitken (1) introduced an outstanding advance in the approach to decision making regarding drugs sampling. Unfortunately this approach has not, as yet, been widely implemented despite being based on a solid mathematical foundation. In this paper we advocate a Bayesian approach along the lines of that outlined by Aitken but designed to be both easily understood with less mathematical sophistication and implementable using standard EXCEL® software. The emphasis is placed on encouraging the application of this methodology to routine case work by explaining the statistics involved. Minor differences exist between this approach and that of Aitken in both the modeling of the prior probability and in dealing with the discrete nature of the samples. These differences in no way detract from the sound mathematical foundation of the approach.

Keywords:
forensic science, drug sampling, Bayesian inference, probability

Paper ID: JFS15171J
DOI: 10.1520/JFS15171J
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