The trial spent the entire day on a 402 admissibility hearing for DNA mixture statistical evidence. Prosecution expert Dr. Bruce Weir presented his statistical methodology for calculating frequencies of mixed DNA stains from multiple contributors, while defense expert Dr. Renee Shields challenged both his approach and his deviation from National Research Council recommendations. The exchange grew notably tense as the defense questioned whether Weir's assumptions were scientifically valid and biased toward the prosecution. Judge Ito ultimately ruled to admit Weir's statistics but with significant restrictions requiring clear labeling and disclosure of assumptions.

• Judge Ito ordered a 402 foundational hearing required before Dr. Weir could testify to the jury about DNA mixture statistics.
• Defense attorney Thompson sharply cross-examined Weir, accusing him of circular reasoning and biasing calculations against the defendant.
• Dr. Renee Shields testified that Weir's statistical method deviated from National Research Council standards and made unsupported assumptions.
• Sharp exchange where Weir called Thompson's characterization of his methodology 'close to being dishonest.'
• Judge Ito ruled to admit Weir's DNA mixture statistics with restrictions: no reference to known samples, clear disclosure of assumptions, and ranges for two, three, and four contributors.
• Defense successfully objected to presenting mixture statistics alongside existing 'not excluded' percentages, requiring clear vertical labeling of 'Mixture' on the frequency board.