Cell Site Analysis – Defence

The Challenge: CCL Group were approached by a legal firm acting on behalf of two defendants accused of involvement with a shooting that took place in Leeds, July 2018.

The prosecution cell site evidence, produced by police analysts, relied on the location of cell site masts and police survey data from the crime scene. It claimed that some of the call data on the defendants’ phones connected via cells which served the crime scene. The prosecution case also relied on the observation that on the afternoon of the offence, there was a high volume of call traffic between the defendants’ phones in the run up to the shooting.

Overcoming the Challenge: One of CCL’s principal cell site experts, Dr Iain Brodie, hosted a case conference at CCL’s offices to plan a strategy to give the best defence against the prosecution cell site evidence in this case.

The prosecution approach was in conflict with the appeal finding in the case of R v Calland Appeal Court Ruling (Case No: 201705120/C1) which upheld a decision to exclude Cell Site Analysis evidence that had been presented to the court by a Police Analyst on the grounds that:

Comments on the location of a mobile phone based derived from the locations of the masts to which it connected constitute an opinion. Only Expert Witnesses can give opinion evidence in the UK Criminal Justice System, and then only in areas in which they are accepted as expert. It is inappropriate and misleading to ask a non-expert witness to interpret results in the context of a case, as additional knowledge and understanding may be required to do so safely and any answer will be taken as “fact” by the jury.

As an Expert Witness, Dr Brodie and the CCL team were able to utilise the most modern and state-of-the-art ICS-500 radio survey equipment to conduct their own surveys and cell site analysis.

The Result: CCL were able to demonstrate that the cells connected to for the calls made by the defendants’ phones around the time of the shooting were more likely if the defendants had been at their home addresses rather than the crime scene.

Dr Brodie was also able to demonstrate, by examining all of the call data in the days preceding the offence, that the volume of calls between the defendants’ phones on the afternoon of the offence, although high, was not excessive when compared to other days.

Dr Brodie was present advising counsel in court in December 2019 – where the police analysts were obliged to review their own survey data and agree that it was indeed in keeping the defendants being at their home addresses.

Not guilty verdicts were delivered in relation to the defendants for all the counts.

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