Applying a Casework Assessment and Interpretation Approach to Probabilistic Genotyping Results Workshop

Description:

This workshop will give the audience an introduction to casework assessment and interpretation (CAI) approaches for reviewing the outputs (including the likelihood ratio) and diagnostics of probabilistic genotyping software used for the analysis of forensic DNA mixtures. CAI methodology is a formal model for the evaluation of evidence in a balanced, logical, robust and transparent manner.

We will describe the various diagnostics and outputs from such software and give guidance on the assessment of results by way of examples. We will explore issues such as the number of contributors, relatives, and stochastic effects within a mixture. Handouts will be provided.

Learning Outcomes:

1. Improved post-software interpretation of results.
2. The importance of the review of diagnostics and outputs of PG software for casework.
3. Provide guidance for a systematic and holistic approach to evaluating diagnostics
4. Demonstrate an increased confidence for interpreting challenging samples from PG software.

Intended Audience:

This workshop is intended for DNA analysts, supervisors, technical leaders, attorneys, and judges. Attendees should be familiar with the concepts of likelihood ratios, PG software, and genotype weights.

Tentative Agenda:

Dr. Jo Bright will describe the various diagnostics within the STRmix report, how they are calculated, and their behavior – for both typical and atypical interpretations.

Dr. Michael Coble will describe the generation of genotype weights and likelihood ratios with PG reports.

Ms. Teresa Cheromcha will present casework examples of profiles where atypical weights and diagnostics were observed, their detection and their remediation.