Prof. Herbert MacDonell, a forensic scientist and bloodstain pattern analyst living in Corning, New York, testified as a defense witness in the 1995 criminal trial after being called by Peter Neufeld, and later testified in the civil trial. His criminal-trial testimony challenged the prosecution's interpretation of the bloodstained socks; he testified that blood had transferred through one sock without a foot inside and that a stain was consistent with blood being dabbed onto the sock while it was flat. Prosecutor Marcia Clark challenged his methodology, qualifications, and the difference between his report's description of a swipe and his testimony. During the civil trial, plaintiffs' counsel Edward Medvene challenged MacDonell's credibility by citing his varying estimates of the number of blood spheres, his lack of useful notes or testing, and his uncertified home laboratory.