Forensic Evidence Concerning Telephone Data

In many criminal cases, the evidence produced by the prosecution relies heavily upon the interpretation of telephone data. 

The limitations on the prosecution’s finances often mean that only part of the work is carried out, and unless the defence understand that far more data or information can and should be analysed, then wrongful convictions can take place. Cellsite evidence is complicated but for the purposes, but here we consider a simplified version.  

Mobile telephones operate by linking to masts depending on the contract server. The telephone companies retain data as to which masts the telephone connected to at a certain time.  Sometimes it is possible to triangulate and find that the telephone was connected to a number of masts. The prosecution often claim that this enables them to place a defendant in an area where a crime was committed. 

They are often wrong.  

The geographical location, buildings, hills, even trees can affect which masts to which a telephone connects. 

We have experts who will actually carry out a survey and determine whether what seems to be the obvious mast, is in fact not the nearest mast for the purposes of telephone data. Cellsite analysis produced by the prosecution is often presented by people who are not experts.   It is essential to have expert evidence and not rely upon data interpreted by police officers. 

We have learned to be very careful about inferences from data. 

Sometimes it is claimed that the frequency of contact between two telephones, at the time a crime was about to be committed, is evidence of collusion or conspiracy to commit that crime.  It is relatively easy to prepare an analysis of the frequency and pattern of telephone calls outside the period leading up to the crime, but unfortunately some lawyers do not carry out this work.

So in one very high profile case, we obtained from the prosecution an admission that the pattern and frequency of telephone calls outside the conspiracy period matched that within the conspiracy period.  As a result the judge withdrew the case from the jury, and directed that the defendant be acquitted.  We have IT specialists within our team who can carry out this analysis in a focused manner.

Cellsite analysis evidence is a developing and growing science, and clients need a lawyer who is keeping up to date with and abreast of the developments.

We are hugely experienced, capable and have an outstanding track record of success. If you are involved in a case involving this type of complex forensic evidence, please contact our Criminal Defence team as soon as possible.


  • John Ellwood
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