The analysis compared four New York counties that established police-prosecutor liaison programs, which included a liaison officer, with two counties that lacked such programs. The research examined 3,692 felony arrests made by State police in the 6 counties. Case processing during the program period of January 1985 through July 1983 was compared with data from January 1983 through December 1984. Interviews with prosecutors and the liaison officers provided additional information. Results showed that the program had only modest effects on case attrition. The effects were limited to enhancing the quality rather than the quantity of convictions, in the sense that more convictions were for all the arraignment charges or the highest arraignment charge. Results also suggested that most case attrition results from efforts by prosecutors to reach just outcomes rather than from ineffective case preparation and call into question the mainly negative interpretations attached to the process of case attrition. Tables, notes, and 10 references (Author abstract modified)