LAPD criminalist Gregory Matheson dominated the day with direct examination testimony on serology evidence, with the prosecution establishing that blood drop 49 matched only OJ Simpson and that the reference vial contained the correct amount of blood, undermining the defense planting theory. However, Blasier's cross-examination revealed critical gaps in crime lab oversight, certification, and training practices. Most dramatically, the day ended with disclosure of a witness coaching scandal in which Matheson and other supervisors had coached criminalist Mazzola on her testimony.

• Matheson confirms blood reference vial contained 3.8ml, not his 2ml visual estimate, undermining defense theory of evidence planting
• Blood drop 49 from Bundy crime scene matches only OJ Simpson and excludes both victims
• Item 118 knife found near Simpson's estate tests as EAP type B, matching victims' nail scrapings, prompting court review
• Cross-examination reveals LAPD crime lab lacks meaningful external accreditation, training standards, and professional oversight
• Witness coaching scandal disclosed: Matheson, lab director Kestler, and Yamauchi coached criminalist Mazzola on testimony style and anticipated questions