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Monte Carlo Bayesian Identification Using STR Profiles

NCJ Number
Donald I. Promish M.S.
Date Published
52 pages

This report provides a description and a case analysis for the Monte Carlo Bayesian (MCB) method in an STR (short tandem repeat) profile.


The Monte Carlo Bayesian (MCB) method described in this report bears out the premise that a complete CODIS 13 STR (short tandem repeat) profile contains all the information necessary to establish the probability that two individuals who both have that profile are really the same person. In order to do so, this paper combines three concepts: the concept of the culprit as a member of a group; the concept of the suspect as a one-person group; and the concept of groups, other than the suspect, which are distinguishable only by their homozygosity. It shows how to perform a Bayesian analysis of an STR profile with respect to the suspect group and a random sample of non-suspect groups. It demonstrates the robustness of the method with respect to a varied selection of real profiles and with respect to evidence other than the profiles. On the grounds that someone who is inbred with regard to the CODIS 13 is even more inbred with regard to the genome, it seems that MCB might be usefully employed to find “leads” to groups at risk for genetic disease. Appendix and references