Police Commissioner Raymond W. Kelly’s appointment of three former federal prosecutors to evaluate the integrity of the Police Department’s internal system for recording crime data has posed the panel with a weighty task. But first it faces a more mundane question: how to proceed…Donna Lieberman, executive director of the New York Civil Liberties Union, said that she was skeptical about the panel. “The question for us is whether the Police Department is simply trying to polish its image or really trying to identify problems in law enforcement practices,” she said. Ms. Lieberman also questioned how Mr. Kelly could pick the monitors to analyze his own agency.