IT TAKES a long time after a lot of reform for a police department to shake a bad public image, as the Prince George's County police has reason to know. That makes it important news that a Maryland NAACP report on police brutality has just termed the Prince George's department the "most improved" -- even if this ranking does not find the department to be Maryland's best. A committee of the state NAACP commends the county for urging 50 changes to improve police relations with residents. County officials deserve credit for the efforts that are now underway.

Charles Jerome Ware, NAACP state general counsel and author of the report, concludes that county leaders have "at least acknowledged they have a problem. They didn't have a choice. It was really bad down there. They had no place to go but up." County Executive Parris N. Glendening and Police Chief David Mitchell are understandably pleased, but as Chief Mitchell hastens to add, "Certainly we have a lot of work to do. But this is positive reinforcement that we're on the right track." According to the chief, complaints brought against the department for using excessive force have fallen by 14 percent since last year; these complaints had dipped from 62 to 50 the year before.

Statistics like these are indicators of a certain progress, but they cannot calibrate the intangible factors in the public's perception of its officers' conduct on the street. What an arresting or inquiring police officer says to an individual can be an offense too. The way in which officers approach people, hear them out and react weigh heavily in the public's evaluation.

Questions of police conduct are best answered by establishing clear policies that set a tone of professionalism and civic responsibility. This pays off for police and for the people they protect: with better police-community relations comes improved law enforcement. For conscientious men and women of the Prince George's police, the comments of the NAACP should serve as an additional incentive on the job.