Every time a telephone call is made electronic fingerprints remain scattered throughout the telephone network. Knowing how to locate, identify and gather this high-tech evidence can aid in reconstructing events and track user movement. Law Enforcement investigators and analysts know telephone companies can provide call records and/or invoices for long-distance calls placed from a subscriber (suspect) line. What they may not be aware of, are the many other types of call records available, where they are, and what to request when preparing a subpoena or court order.The analysis of call records can be daunting as there are many types; some are simple and straight forward while others technical and complex. However, the information provided in this text can aid in a successful assessment.