A Project of the University of Michigan Law School and the MDefenders Program

This motion relies on the Federal Rules of Evidence to argue for exclusion of expert DNA testimony about the likelihood ratio obtained using STRMix probabilistic genotyping software. Pages 5-8 describe the basic steps of DNA extraction and analysis. Pages 8-9 discuss the problems of trace DNA and the possibility of innocent transfer of DNA.  Page 11 explains how DNA analysis is less reliable when there is a complex DNA mixture and pages 12-15 discuss the danger that jurors will misunderstand (and prosecutors will misrepresent) what a likelihood ratio actually means.

File Type: docx
File Size: 48 KB
Categories: 403, DNA, DNA Mixture, Evidence, Expert Testimony, Forensics, Improper Argument by Prosecutor, Juries, Juror Psychology, Likelihood Ratio, Secondary Transfer, Witnesses
Author: National, Washington