Understanding Cell Site Analysis in Criminal Investigations

20 October 2023

At IntaForensics our cell site experts undertake high-profile criminal cases for both prosecution and defence clients, giving them a broad, complete and unbiased perspective on the movements of a mobile device.   

With the increasing prevalence of mobile phones in society, but also in criminal cases, understanding cell site analysis can be crucial in an investigation. In this article we will explore cell site analysis, and how this type of evidence can assist in your case:  

  • It may help demonstrate that a device could have been present in an area including an incident location or crime scene. 
  • However, it could also suggest otherwise – potentially supporting an alibi. 

What is Cell Site Analysis?

Cell Site analysis is a forensically recognised method to help identify an area in which a mobile phone could have been at a particular time.  

Together with Radio Frequency Propagation Surveys (RFPS), cell site analysis can place or map a mobile device in a geographical area, at a certain date and time using mobile call data records. 

Cell Site Analysis - Call Mapping

This is an example of a cell mapping, which is included in appendices with the accompanying technical report, enabling effective cross referencing between documents.

How does Cell Site Analysis work?

The Call Data Records (CDR’s) of a mobile phone need to be secured from the network provider – these are usually retained for 12 months and requested by the Police under the Investigatory Powers Act. 

These records can be analysed, using specialist software, to determine when the device was used and what cells it connected to during a period of interest.   

A Radio Frequency (RF) survey can then be undertaken, to see if the cells used at a particular time by the device provide coverage at a location relevant to an investigation. 

All work produced is integrated seamlessly in a technical report, with combined call schedules and referencing for all call data records as part of the investigation. These call mapping documents are easy to comprehend and exhibit visual clarity to demonstrate cell site analysis and cell detections. 

Cell Site Analysis - Combine Call Data Records

An example of call data records in a combined schedule.

Cell Site Analysis and Call Data Record Reports for Criminal Investigations

Our experts can produce a report detailing the following information: 

  • Evidential call data, including showing calls between target phones. 
  • Timeline analysis showing the movement of a phone in user defined time periods. 
  • Cell detection maps showing the measured coverage of specific cells detected during Radio Frequency (RF) surveys. 
  • Analytical results, for example activity by hour in a given district postcode area, or contacts common to a group of phone numbers. 
  • Attribution analysis showing the most used cells or overnight cells. 
  • Collocation and non-collocation analysis to consider whether phones could have been located in the same area or were in separate areas at the relevant time. 

All conclusions in the technical reports provided to police forces or legal teams are underpinned by meticulous detailed analysis, evidencing how conclusions were reached. 

Despite the complexities of this subject our staff have excellent verbal communication skills, ensuring that a Jury can understand and follow key aspects of the evidence. Our cell site experts have extensive court experience with regards to cell site analysis; they are permitted to give opinion evidence and provide expert testimony.  

Our cell site team are also adept at dealing with pre-trial enquiries and case conferences, including liaising with other experts.   

How can Cell Site Analysis support your defence case?

If a suspect had a phone on them at the time in which the crime was committed, the police would request call data records for before and after the event. This can be a significant amount of information, including a call schedule, movement maps and analytical tables, with statements by a police analyst and/or expert witness. 

Our experts look at the call data, analyse it, and determine the mobile phone’s movements, specifically around the dates and times that the police are interested in. This report helps defence teams to answer: 

  • Has the prosecution’s expert correctly interpreted the call event data? 
  • Are there any alternative hypotheses to consider? 

Work with IntaForensics

IntaForensics are the first organisation to be granted ISO/IEC 17025 accreditation for cell site analysis in the UK. This accreditation demonstrates the technical competence of IntaForensics and offers all our private and public sector clients the confidence in our technical reports.  

Our team of cell site analysts have years of experience working in law enforcement and can apply their specialist knowledge when completing case reviews for defence teams. All our reports are presented in a straightforward and accessible manner for the lay reader, and all work is peer reviewed and subjected to rigorous quality checks at key stages. 

Get in touch with our experts at IntaForensics to find out how they can use cell site analysis and call data records to support your criminal investigation or defence strategy at sales@intaforensics.com or 0247 77 17780. 

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