Brian "Kato" Kaelin was the houseguest living at O.J. Simpson's Rockingham estate whose testimony about the night of June 12, 1994, placed him at the center of the prosecution's timeline — he described hearing three loud thumps on his bedroom wall around 10:40 PM along the south pathway and observed Simpson's insistence on retrieving a mysterious dark knapsack before departing for the airport. His credibility was contested: Marcia Clark aggressively impeached him by surfacing violent domestic incidents he had omitted from his grand jury testimony and argued he could not account for Simpson's whereabouts during the critical window, while Robert Shapiro used cross-examination to portray Simpson as calm and untroubled that evening. Kaelin's testimony spanned multiple days in both the criminal and civil trials, where the defense exposed $60,000 in earnings connected to the case and his limited direct knowledge of the relationship between Simpson and Nicole Brown.