Gary Sims, a criminalist with the California Department of Justice, was one of the prosecution's central DNA witnesses, presenting RFLP and PCR analysis over twelve days of testimony that linked blood evidence from the Bronco, the Rockingham glove, Simpson's socks, and the Bundy crime scene to Simpson and the victims — including a statistic of 1-in-21-billion odds for Nicole Brown Simpson's blood on a bedroom sock. Examined by prosecutor Rockne Harmon and cross-examined at length by Barry Scheck, Sims became a focal point of the defense's contamination and planting theories, particularly around a rear gate blood sample with 270 times more DNA than other crime scene stains and Bronco samples that showed dramatic increases in DNA content over time. Before he even took the stand, Sims was at the center of a heated discovery dispute over ongoing RFLP testing at the DOJ lab, with Scheck accusing the prosecution of engineering a "forensic ambush" and seeking preclusion of the results. Sims returned to testify again in the civil trial, where defense attorney Blasier attacked his lab's interpretation of faint PCR results, error rates, and statistical methodology.