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Monte Carlo Bayesian Interpretation of STR Mixtures

NCJ Number
238781
Author(s)
Donald I. Promish
Date Published
2012
Length
15 pages
Annotation

This essay pertains to the hypothesis that a suspect profile has been contributed to an STR (short tandem repeat) mixture, a problem which appears to underly STR mixture interpretation.

Abstract

This article is an attempt to deal with a problem which appears to underly STR mixture interpretation. The approach has its origins in detection theory, particularly as it relates to the detection of targets in the presence of extraneous signals. At issue is the hypothesis that a suspect profile has been contributed to an STR mixture. The evidence related to the hypothesis is that all of the alleles in the profile, as defined above, appear in the mixture. The profile has N complete loci, and n of those loci are homozygous. A "complete" locus possesses a pair of alleles. In the context of this essay, a locus possessing an unpaired allele is uninformative, because information can be gotten only from the difference (which may be zero) between members of a pair.

Date Published: January 1, 2012