Interpretation of Y chromosome STRs for missing persons cases

Y chromosome STR haplotypes (Y-STRs) have been used in assisting forensic investigations primarily for identification and male lineage determination. However, because of the high mutation rate of Y-STRs, there are complex missing person cases in which inconsistent Y-STR haplotypes between true paternal lineage relatives will arise and cases with two or more male references in the same lineage and yet differ in their haplotypes. Therefore, improved guidelines are needed for interpretation of Y-STR haplotype data. Computational methods and interpretation guidelines have been developed specifically addressing this issue, either using a mismatch based counting method or a pedigree likelihood ratio method. However, these methods and guidelines have not been adopted by forensic laboratories, likely because of a lack of specific procedures and software to facilitate analyses. This proposed project will validate and implement methods and guidelines for Y-STR applications, particularly for complex missing persons cases. A software program will be developed and validated to facilitate Y-STR haplotype interpretation, and the software will be made accessible to the forensic community free of charge with the goal of improving the interpretation of complex cases with Y-STR haplotype evidence. Note: This project contains a research and/or development component, as defined in applicable law, and complies with Part 200 Uniform Requirements - 2 CFR 200.210(a)(14). CA/NCF