Covert measurements came from records made by trained officers who surreptitiously recorded the activities of other officers. Each of the six officers covertly recorded a total of 40 hours of patrol time. These results were compared with those from historical data covering 160 hours and from computer records on police calls for service. The covert observations recorded more activities than recorded by the officers themselves or by the computer records. The computer record also underreported the activities. Total police time reported by the covert observer was nearly 50 percent higher than that recorded on the computer system. The computer record captured less than one-third of the number of arrests reported on the daily log, and the log failed to record all the arrests. Officers rarely recorded their nonpolice activities, although these took only a small amount of police time. Police officers were often out of touch with the dispatcher during an arrest. Other administrative implications, figures, and footnotes are supplied.