Susan Brockbank was an LAPD criminalist assigned to the trace analysis unit, where she specialized in hair and fiber evidence. Called by the prosecution in late June 1995, she testified across two days under direct examination by Marcia Clark about the hair and trace work she had performed on the case since being assigned on June 21, 1994. Her testimony became a flashpoint for the defense when cross-examination by Robert Blasier exposed serious evidence-handling problems, most notably that items from three different crime scenes — both gloves, the Bronco carpet sample, and the knit cap — had been stored together in a single box containing 446 items, raising critical contamination questions that undermined the prosecution's forensic chain of custody.