Dr. William Shields, a population geneticist from SUNY-ESF, testified for the defense during a pivotal admissibility hearing on DNA mixture statistics. He challenged prosecution expert Dr. Bruce Weir's methodology for calculating the frequency of mixed DNA stains from multiple contributors, arguing that Weir's approach deviated from National Research Council recommendations. The hearing, which consumed an entire day, underscored the defense's broader strategy of contesting not the DNA evidence itself but the statistical framework used to interpret it.