A priori probabilities in Y23 mixture analysis: Non-contributor experiments using simulated powerplex® Y23 Y-STR mixtures. (December 2017)

• Record Type: Journal Article
• Authors: Moore, D.; Clayton, T.; Thomson, J.
• Is Part Of: Forensic science international. Volume 6(2017)
• Page Start: e74
• Page End: e76
• Publication Date: 2017-12
• Subjects: Y-STR -- Mixture evaluation -- Non-contributor; Forensic genetics -- Periodicals; Forensic Genetics -- Periodicals; Electronic journals; 614.1
• DOI: 10.1016/j.fsigss.2017.09.052
• Languages: English
• ISSNs: 1875-1768

Abstract

Abstract: When Y-STRs are used in the investigation of sexual offences, it is not uncommon to observe mixed profiles from two or more male individuals. If the haplotype of a person of interest is fully represented in the mixed profile then clearly that male could not be excluded as a possible contributor to that mixture. The evaluation of the weight-of-evidence in such cases is more complex than in autosomal STRs (where the loci are inherited independently). Methods for calculating a likelihood ratio for a Y-STR mixture have been published (Wolf et al.[1] ). However, these methods require complex mathematics to perform. To further our understanding of the significance of a match within a Y-STR mixture we have devised a non-contributor experiment on simulated mixtures derived from published PowerPlex® Y23 haplotypes from 19, 630 different men[2] to estimate the average probability of a random inclusion (P i ).