Day 41 centered entirely on Robert Shapiro's methodical cross-examination of Detective Philip Vannatter, the lead investigator. Shapiro systematically dismantled the prosecution's case by exposing critical failures in investigation protocols, chain-of-custody procedures, crime scene management, and Vannatter's own credibility. The judge had already ruled that Vannatter made search warrant statements with 'reckless disregard for the truth,' and Shapiro's examination reinforced this finding through detailed contradictions and violations of basic detective work standards.

• Shapiro had Simpson display his allegedly injured finger directly to the jury, challenging the prosecution's timeline
• Vannatter admitted a trainee criminalist with minimal experience was sent to the Bundy crime scene
• No murder weapon was ever found despite exhaustive searches in multiple states and countries
• Shapiro exposed that Vannatter entered the Rockingham estate without a warrant, using no protective gear or tactical procedures
• 24 people were present at the Bundy crime scene before Vannatter arrived, and no notes were taken at Rockingham before 7 AM
• Judge Ito had already ruled Vannatter made search warrant statements with 'reckless disregard for the truth'
• Shapiro established that Vannatter lacked formal DNA training and failed to consult the best available experts