Cell phones may maintain a connection to cell towers whether the device is in use.  Each time a mobile device connects to a cell tower mass amounts of data are collected and stored.  These records along with usage data composes what is called Call Detail Records (CDR).

CDR generate information when the cell phone utilized data services, such as the internet, email, video calls, apps and downloads.  The data services can result in a connection between the phone and network.  As the user travels and the mobile device connects to new cell towers, new entries in the CDR are generated that can enable the phone to be tracked through analysis.

The results of the CDR Analysis can be used to show if the accused mobile device was used for calls, SMS events or data sessions at a time or location of interest.  The location during the time of an incident can prove that an individual was at the scene or provide an alibi toward his/her innocence.