Robert Blasier served as the defense team's forensic science specialist, leading the attack on the prosecution's DNA, blood, and trace evidence across both the criminal and civil trials. He conducted extensive cross-examinations of criminalists and lab analysts — most notably LAPD's Gregory Matheson, where he exposed gaps in crime lab oversight and established that approximately 1.5 milliliters of Simpson's reference blood were unaccounted for, and FBI chemist Roger Martz, whose EDTA testing methodology he challenged as flawed. Blasier also delivered a portion of the defense's closing argument in the civil trial, systematically challenging the physical evidence chain and highlighting LAPD documentation failures, evidence handling irregularities, and lab error rates that he argued undermined the reliability of the forensic case.