The first in a series of Q&As with our cell site team, with our experts coming together to help develop awareness and understanding of this emergent forensic discipline
CCL has one of the largest, and best regarded team of cell site analysts in the UK. They are regularly involved in delivering expert evidence in court and their work and testimony are often cited by police investigation teams as playing a pivotal role in securing convictions.
With cell site continuing to evolve and mature as a forensic science, against the backdrop of a fast-changing technological world, we thought the occasional Q&A drop-in with the team would be useful.
In each Q&A we ask the same question across the team and bring you the best of the answers.
In this first outing, we let them vent on a favourite topic!
What are the main misconceptions around cell site that you regularly encounter in your day-to-day work?
“People overestimating the level of precision that cell site can give or thinking they can essentially “cross reference" the results of a survey against individual call events.
I had a case where an analyst, after receiving a report, contacted me querying a single call event, which was believed to place the phone closer to a location of Interest. Looking at the single event in isolation did indeed appear to put the phone closer to the location; but when looked at in the full context of the call data the phone appeared further away, as was stated in the report.
Also, I have had cases where I have been asked to provide a list of cells "that would serve a location", that could then be used by the requesting client to look-up against the call data - risking running into similar issues as above.”
“That a superficial view, merely cross correlating survey results and CDRs, Is acceptable. Performing a robust, transparent, logical and balanced analysis takes time.”
“The main misconception in my view? That survey equipment is the only tool needed to provide the answers to cell coverage. Survey tools only provide a sample of the serving cells on the air interface and just to rely on a print-out from a survey tool while not understanding the context is a risk.”
“There is a misconception that using a single validated type of equipment can satisfy the purposes of a survey. This is most likely a legacy from the days when only 2G and 3G were in service.
However, today the mobile network infrastructure is rapidly changing to meet the demands of society for a 5G service. 3G technology is gradually being phased out. New 4G technology bands are being created by the networks. In summary, the 'air interface' has evolved and is still rapidly changing.
Best practice has always required more than one type of equipment be used in parallel to satisfy the purposes of a survey. Today, such 'best practice' has become a fundamental 'necessity' as opposed to 'something we would like to achieve but require more funding'.”
“It is often assumed that cell site analysis can pinpoint the exact location of an individual. It is important that the limitations of cell site are clear when presenting your evidence, most commonly that we cannot identify the user of a phone or exactly where that phone was. Instead, we can identify an area that the phone could have been or movement of a phone between areas.”