The study involved juries in 27 New York counties and jury acquittal rates in those counties over the 10-year period between 1986 and 1995. Data on 35,595 verdicts were analyzed. The percentage of blacks and Hispanics in a county's population varied from a low of 2.4 percent (St. Lawrence County) to a high of 74.1 percent (Bronx County). The range of acquittal rates varied between 12.3 percent in Ontario County to 38.4 percent in the Bronx. The data strongly suggested the presence of black and Hispanic jurors made a difference in jury conviction rates from county to county. Juror race was more significant in doubtful cases than in open-and-shut cases, and juries with significant black and Hispanic representation acquitted more than juries without such representation. Factors affecting juror treatment of the evidence and variations in jury behavior are discussed. 48 notes and 3 tables