A mobile communication device that may be used by an investigator to secretly record a suspect and track the investigator's location includes a microphone for detecting sounds, a communication component for transmitting signals or data representative of the sounds to one of the portable computers via the wireless communication network, a display for displaying information related to operation of the device, a computing device, and a computer program implemented by the computing device. The computer program is operable to place the device in a stealth mode in which the display is turned off or otherwise deactivated to make the entire device appear to be turned off while the microphone continues to detect sounds and the communication component continues to transmit signals or data representative of the sounds to a surveillance or support team operating one of the portable computers. The mobile communication device may also include a location-determining component for determining geographic locations of the device and for transmitting location data to the portable computer.