Det. Philip Vannatter served as the lead LAPD investigator on the case and became a central target of the defense's strategy to discredit the police investigation. Called by both sides across the criminal and civil trials, he faced methodical cross-examinations — particularly from Robert Shapiro — that exposed critical failures in evidence handling, chain-of-custody procedures, and the accuracy of his search warrant affidavit, including transporting an unrefrigerated blood sample in his car for two hours and statements the judge ruled were misleading. His testimony about the decision to go from the Bundy crime scene to Simpson's Rockingham estate became a flashpoint, and during closing arguments the defense argued Vannatter had planted blood evidence — a charge the prosecution countered by pointing to DNA science and logical impossibilities.