Systems and methods for tracking mobile devices are provided. One system comprises at least one processor and memory storing code which when executed by the at least one processor configure the at least one processor to perform a method of tracking a mobile device. The method comprises receiving a disassemble international mobile subscriber identity (IMSI) attach message from a base station, identifying the identified mobile device within a location area using the IMSI and LAI, receiving a decode and capture message from the base station, and identifying the unidentified mobile device as being the identified mobile device within the location area. The disassemble IMSI attach message includes an IMSI and a location area identity (LAI) associated with an identified mobile device. The decode and capture message includes a temporary mobile subscriber identity (TMSI) and LAI associated with an unidentified mobile device.