Using Probabilistic Theory To Develop Interpretation Guidelines for Y-STR Profiles

• NCJ Number: 250070
• Author(s): D. Taylor, J. A. Bright, J. Buckleton
• Date Published: March 2016
• Length: 13 pages
• Agencies: NIJ-Sponsored
• Award: Population Genetic Issues for Forensic DNA Profiles

Annotation

This article presents a probabilistic model for the interpretation of Y-STR data, and due to the fact that probabilistic systems for Y-STR data are still some way from reaching active casework, it also describes how data can be analyzed in a continuous way to generate interpretational thresholds and guidelines.

Abstract

Y-STR profiling makes up a small but important proportion of forensic DNA casework. Often Y-STR profiles are used when autosomal profiling has failed to yield an informative result. Consequently Y-STR profiles are often from the most challenging samples. In addition to these points, Y-STR loci are linked, meaning that evaluation of haplotype probabilities are either based on overly simplified counting methods or computationally costly genetic models, neither of which extend well to the evaluation of mixed Y-STR data. For all of these reasons Y-STR data analysis has not seen the same advances as autosomal STR data. (Publisher abstract modified)