Barry Scheck served as a defense attorney and DNA expert, focusing on the collection, chain of custody, documentation, and laboratory handling of physical evidence. During his multi-day cross-examination of LAPD criminalist Dennis Fung, Scheck used crime-scene videotapes and records to question Fung's recollection and timeline, the reliance on “oral tradition” rather than written laboratory procedures, the storage of wet blood swatches, and the handling and delayed booking of Simpson's reference blood vial. He also examined forensic witnesses including Collin Yamauchi, Gary Sims, Dr. John Gerdes, Dr. Henry Lee, Douglas Deedrick, William Bodziak, and Detective Kelly Mulldorfer.