The defense methodically dismantled the prosecution's evidence handling practices through an intensive cross-examination of LAPD criminalist supervisor Gregory Matheson, extracting concessions about the lab's lack of accreditation, absence of formal procedures, and systematic failures in chain of custody. Matheson was forced to acknowledge critical deficiencies including unrefrigerated blood storage, incomplete crime scene documentation, socks left unexamined for months, an incompletely searched Bronco, and an undocumented lab contamination outbreak. The day also featured motions on Kardashian's potential testimony regarding a missing garment bag and allegations that prosecutors improperly contacted defense experts.

• Matheson conceded the LAPD crime lab lacked accreditation and had no formal field operations manual since 1992
• Defense exposed that crime scene checklists from June 13th were incomplete with blank sections on scene alterations
• Socks evidence was ignored for 2-3 months, never photographed before being cut and altered
• Matheson admitted different evidence documentation standards were applied when defense observers were present versus routine lab work
• Lab applied same swab to multiple Bronco pedals and stored wet bloodstains in plastic for up to seven hours
• Bronco blood evidence was incompletely collected in initial search, with blood later discovered
• LAPD DNA lab experienced an undocumented contamination outbreak of unknown duration
• Blood found on the outside of victim reference vials
• Court heard motion on Robert Kardashian's potential testimony regarding missing Louis Vuitton garment bag from June 13
• Defense alleged prosecutor Rockne Harmon improperly contacted defense DNA experts through FBI agent to discover secret EDTA testing