This module originally occurred on June 26, 2019
Duration: 4 hours
Module 7: Uncertainty and Limitations of Probabilistic Genotyping Systems
Has a person of interest contributed DNA to a mixture obtained from evidence? Is that DNA associated with a crime? Both are questions that cannot be answered with absolute certainty. This module of the Probabilistic Genotyping of Evidentiary DNA Typing Results workshop series addresses the uncertainty and limitations of probabilistic genotyping systems that are used to calculate likelihood ratios and infer genotype sets from DNA typing results. Probabilistic reasoning provides a means to characterize these results, given the unknown information in forensic evidence, the stochastic environment, and sources of variability. Instructors in Module 7 will explore strategies of interpretation and decision making in light of these and other variables, such as the uncertain number of contributors, and will share research on the impact of these variables on the likelihood ratio.
Additionally, courts are becoming increasingly interested not just in “whose DNA is this?” but “how did the DNA get there?” Therefore, the instructors will revisit topics introduced earlier in the series to dive deeper into the relevance of a DNA profile, given today’s advanced detection sensitivity and the potential for DNA transfer, as well as activity level reporting and the hierarchy of propositions.
Detailed Learning Objectives
- Describe sources of uncertainty in mixture interpretation and their influence on the likelihood ratio
- Devise a strategy to address contributor number assignment/re-assignment
- Address questions regarding the potential for DNA to be transferred through contact and persist on evidence
- Be aware of developments that assist the courts in considering activity level propositions
- Amke Caliebe | University of Kiel, Kiel, Germany
- Zane Kerr | Institute on Environmental Science and Research, Auckland, New Zealand
- Klaas Slooten | Netherlands Forensic Institute & Vrije University, Amsterdam, The Netherlands
- Bianca Szkuta | Victoria Police Forensic Services Department & Deakin University, Geelong, Australia
Funding for this Forensic Technology Center of Excellence webinar has been provided by the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice.
The opinions, findings, and conclusions or recommendations expressed in this webinar are those of the presenter(s) and do not necessarily reflect those of the U.S. Department of Justice.
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