Representation of Statistical Weight to Stakeholders and the Court

Historically, the predominant means of assigning statistical weight to many DNA mixtures in the U.S. has been the combined probability of inclusion, or CPI. Accordingly, many forensic DNA analysts, as well as attorneys and judges, are well-versed in the CPI as a match probability. In the fifth module of this workshop series devoted to probabilistic genotyping, the presenters will help DNA analysts and legal professionals understand degrees of statistical weight and properly communicate likelihood ratios and their meaning. The SWGDAM recommendations for reporting likelihood ratios will be discussed, along with an explanation of the empirical basis for its verbal scale that may be used in reports and testimony along with the likelihood ratio. Participants’ ears will also be tuned to lines of questioning that could lead to a fallacious statement about the statistic.

This webinar is part 5 of the Probabilistic Genotyping Of Evidentiary DNA Typing Results Webinar Series and was presented by the NIJ Forensic Technology Center of Excellence on June 8, 2019.