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Research Article| Volume 16, P71-76, May 2015

Inclusion probability with dropout: An operational formula

  • E. Milot
    Correspondence
    Corresponding author at: Département de chimie, biochimie et physique, Université du Québec à Trois-Rivières, 3351 boul. des Forges, CP 500, Trois-Rivières, QC, Canada G9A 5H7. Tel.: +1 819 376 5011x4397.
    Affiliations
    Département de chimie, biochimie et physique, Université du Québec à Trois-Rivières, 3351 boul. des Forges, CP 500, Trois-Rivières, QC, Canada G9A 5H7

    Centre international de criminologie comparée, Université du Québec à Trois-Rivières, 3351 boul. des Forges, CP 500, Trois-Rivières, QC, Canada G9A 5H7
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  • J. Courteau
    Affiliations
    Groupe de recherche PRIMUS, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, 3001, 12e Avenue N., Sherbrooke, QC, Canada J1H 5N4
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  • F. Crispino
    Affiliations
    Département de chimie, biochimie et physique, Université du Québec à Trois-Rivières, 3351 boul. des Forges, CP 500, Trois-Rivières, QC, Canada G9A 5H7

    Centre international de criminologie comparée, Université du Québec à Trois-Rivières, 3351 boul. des Forges, CP 500, Trois-Rivières, QC, Canada G9A 5H7
    Search for articles by this author
  • F. Mailly
    Affiliations
    Laboratoire de sciences judiciaires et de médecine légale, Ministère de la sécurité publique du Québec, 1701, rue Parthenais, Montréal, QC, Canada H2K 3S7
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Published:December 04, 2014DOI:https://doi.org/10.1016/j.fsigen.2014.11.023

      Abstract

      In forensic genetics, a mixture of two or more contributors to a DNA profile is often interpreted using the inclusion probabilities theory. In this paper, we present a general formula for estimating the probability of inclusion (PI, also known as the RMNE probability) from a subset of visible alleles when dropouts are possible. This one-locus formula can easily be extended to multiple loci using the cumulative probability of inclusion. We show that an exact formulation requires fixing the number of contributors, hence to slightly modify the classic interpretation of the PI. We discuss the implications of our results for the enduring debate over the use of PI vs likelihood ratio approaches within the context of low template amplifications.

      Keywords

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