Systems Thinking and DNA Mixtures: Dynamic Models, Optimization, Validation and Inference
Monday September 24th, 2018 // 8:30 am - 5:00 pm
This workshop introduces systems thinking with demonstrations on applying a systems approach to forensic DNA mixture interpretation, optimization and validation. Topics to be covered include validation of the DNA interpretation pipeline containing probabilistic genotyping software, focusing on current and forthcoming OSAC/ASB and SWGDAM mixture interpretation validation and verification standards and guidelines. Also included will be a review of published literature with discussions on the foundational validity of mixture interpretation and the impact of laboratory accreditation. Future directions for improving front end processing steps will also be discussed.
By the end of the workshop attendees will:
- Be cognizant of why a systems thinking approach to validation will positively impact mixture interpretation results and probabilistic genotyping outcomes
- Have explored the entire post-extraction laboratory system (quantification to LR computation) using a dynamic model parameterized by experimental data. We shall demonstrate that the entire process can be evaluated in a cost- and time-efficient manner by surveying common laboratory parameters such as cycle number, injection time, and analytical thresholds
- Have explored methods to quantify the impact of their processing decisions on the likelihood ratio and its distribution
- Understand the differences and relationships between sensitivity, resolution, analytical thresholds, and other relevant analytical figures
- Recognize the differences and relationships between accreditation, validation, optimization and verification within the laboratory’s DNA testing and interpretation processes
- Be exposed to a comprehensive review of mixture interpretation publications and findings from the NIST DNA Mixture Review that should be published in July 2018
- Be better informed on the standards for mixture interpretation, protocol development, and probabilistic genotyping validation and recognize the limits of data and mixture interpretation
DNA Technical Leaders, Laboratory Directors, DNA analysts, QA/QC managers, attorneys, academicians, consultants and aspiring DNA analysts.
Pre-requisites include: Experience with forensic DNA profiling techniques and STR data interpretation. Minimal working knowledge or experience with genotyping software would be helpful but is not required.
Assistant Professor, Program in Biomedical Forensic Sciences, Boston University School of Medicine
Catherine Grgicak is an Associate Professor and Henry Rutgers Chair in the Department of Chemistry at Rutgers University in Camden NJ. Her Laboratory for Forensic Technology and Integration is a research laboratory focused on the development of systems and procedures to improve forensically relevant bio-analytical processes.Submit Questions
NIST Fellow & Special Assistant to the Director at the National Institute of Standards and Technology
John M. Butler is an internationally recognized expert in forensic DNA analysis and holds a Ph.D. in analytical chemistry from the University of Virginia. He has written five textbooks on Forensic DNA Typing (2001, 2005, 2010, 2012, and 2015) and given hundreds of invited talks to scientists, lawyers, and members of the general public throughout the United States and in 25 other countries so far.Submit Questions
Associate Professor and Director of the Biomedical Forensic Sciences Program, Boston University
In the past 20 years Dr. Cotton has testified as an expert in DNA analysis in over 250 criminal cases (admissibility hearing and trials) in 35 states. She serves on the Editorial Board of the Journal of Forensic Sciences and served two terms as an elected member of the Board of Directors of the American Society of Crime Laboratory Directors/Laboratory Accreditation Board.Submit Questions
Charlotte Word is currently a consultant in Human DNA Identification testing. She has performed technical reviews on many 1000’s of cases from several public and private DNA testing laboratories and has participated in the validation of various DNA test systems. Charlotte has testified as an expert witness in over 300 trials and admissibility hearings around the country since 1990.Submit Questions