Cell Site Analysis is the investigation of electronic data records obtained from a mobile service provider to determine the location of a mobile phone SIM card and/or handset at the time voice calls, short messages (SMS), multi-media messages (MMS) or data connections were made.
Cell Site Analysis (CSA) is used to reconstruct the physical movements of a mobile phone or other communication device. Such evidence can be used by investigators to establish a connection between individuals, proximity to a crime scene, a suspect’s movements and as a means of testing the strength of an alibi.
It is important that Cell Site Analysis is undertaken following strict guidelines set down by the Association of Chief Police Officers (ACPO) so that best practice is maintained.
The Technology
Mobile phone networks are based on short range radio communication between the handset and the transmitter/receiver, known as the Cell Site. The UK alone is covered with thousands of such Cell Sites. Every event which requires communication between the handset and the Cell Site such as a voice call or messaging will leave a record, primarily for the purposes of billing.
Cell Site Analysis (CSA) information can be used by an expert, in conjunction with data about the transmitter masts, to build up a pattern of usage for the mobile phone under investigation. This data can build up a picture of the phone’s location and usage during any given time period.
CSA, What is Possible
Cell Site Analysis (CSA) can ascertain the likely location of a mobile phone using detailed examination of historic voice call records, used in conjunction with mobile network analysis. The conclusions are used to predict the location of the mobile phone under analysis at specified times as part of an investigation.
While a mobile phone and SIM card may be registered to a particularly subscriber, it is essential to understand that because they are mobile, they could be used by somebody else. Further evidence is required to attribute the phone with a user, such as the voice call log and text messages.
