The NBPD's installation of in-car video was spurred by Federal charges of a civil rights violation by the department in 1996. The department was convinced that if there had been a videotape of the alleged incident, the court would have sided with the NBPD officers. Thus, the primary incentive for the decision to install in-car video was to have a means of obtaining audiovisual evidence of events that occur in the course of a patrol stop, so as to be able to answer any suspect charge of a civil rights violation. Departmental policy requires officers to activate the system every time they initiate any activity from their vehicle. The system also automatically begins operation when the vehicle's emergency lights are turned on. The system includes a wireless, belt-worn microphone that transmits audio up to 1,000 feet from the car. The department is currently working on a means for automatically activating the microphone when an officer moves away from the car radio, since, unlike the video camera, the microphone does not currently activate automatically. A California law requires that all law enforcement agencies in the State maintain in-car videotapes for a minimum of 1 year, whether or not they contain evidence. The NBPD has implemented a barcoding and tracking system that facilitates the storage, dating, and retrieval of the department's 18,000 videotapes, which are kept in a secure evidence locker.