Pump Court Chambers

Manslaughter: Having your Cake and Eating It

Blog 7th January 2022
Sarah Jones QC

In June 2021 Salisbury Crown Court heard an interesting case of manslaughter (in which I acted for the Defendant along with Tessa Shroff) that came about by reason of the family of the victim’s right to review. It gave rise to considerations of the propriety of the Crown trying to run a prosecution on two mutually inconsistent factual bases. It also raised fascinating evidential issues relating to GNSS technology and the accuracy of a phone in revealing the location of its carrier.


The Factual Background

The deceased came to be lying in the road in the dark after a night of drinking with a group of people he had met that night, one of which was the Defendant. Two cars then  ran over him in circumstances which an accident investigator and anyone with an understanding of the road layout and prevailing conditions could only have concluded were no fault of both drivers. The victim sustained catastrophic injuries and was pronounced dead at the scene. A police investigation ensued.


It transpired that the victim, B, had left the home nearby of one of the people with whom he had been drinking called C. He was extremely drunk and, presumably accidentally, took C’s phone with him as he left. C went looking for him and on finding him punched him and took his jacket. Not many minutes later B was seen lying in the road a short walk away shortly before he was driven over. The Crown’s case against the Defendant D was based on the evidence of C and his friend M that they had come to find B and seen D walking away from him and when they asked what had happened, D was alleged to have said he had knocked B out. D was interviewed and said that although he could not be sure of timings, he had left the party house after C had returned with his phone but before the accident had occurred and walked home without any knowledge of the tragedy. He had not punched the victim and he could not say whether anyone else had or whether the victim has simply fallen through drunkenness. The phone in his pocket was analysed by police and in particular, the location data analysed and a case was made that this proved he had lied and he had not only left after the accident but location data placed him exactly at the point C and M had placed him at when they said he had made his confession.


Two Types of Manslaughter – one count on the Indictment

The Crown’s primary case was that this was an unlawful act manslaughter – the Defendant had unlawfully punched B causing him to be unconscious and prone in the road in the circumstances which caused his death. However, they served a note with the indictment indicating that should it be necessary or desirable the jury ought to be invited to return alternatively a verdict of gross negligence manslaughter – namely that even if D had not committed an unlawful act, to have left B lying in the road where he had caused or contributed to this state of affairs and thereby created a duty of care on him to take reasonable steps to save B’s life amounted to manslaughter.


They relied on the case of R v Evans (Gemma) [2009] 2 Cr.App.R 10 where the Appellant’s supply of heroin to her sister and failure to call for an ambulance when she overdosed led to her conviction for manslaughter. However the notion that in a case where the Crown were allowing for the factual possibility that D may have punched out in lawful self defence he thereby created for himself a duty of care to return to the prone body of his assailant and pull him out of harm’s way is one that we for the Defence were unable to find support for in the authorities. Nor did it sit right with us for the Crown to allege on the one hand manslaughter based on an unprovoked attack on B by D but in the alternative assert manslaughter based on a blow in self defence. In the end the trial judge Garnham J did not direct the jury in respect of the gross negligence manslaughter and the case centered on the allegation of an unlawful act.


GNSS (Global Navigation Satellite Systems)


The Crown’s expert on phone location technology, if nothing else, made me terrified of the extent to which all those of us who carry a smartphone carry a spy in our pockets. Did you know the right expert can tell whether you have picked your phone up without even unlocking it, never mind what you then did with it and which apps you used once you then unlocked it? Or that they can analyse whether the phone has moved by being walked, jogged or biked to a new location even if the speed of the journey were to be identical in each case?

But my discovery in this case as to the fallibility of location tracking leads me to caution concern with regard to reports that promise confidently of meter by meter tracking. The Crown’s expert produced a list of anomalies on location data where the phones analysed had supplied two different location points with an identical time marking – in effect suggesting the phone had literally been in two places at once. But he maintained that his expertise qualified him to say which was the incorrect location marker by looking at the surrounding data, tracking times, patterns and other data.

The jury clearly concluded this may have been overly confident and they may have been persuaded to this conclusion by the Defence identifying an instance of an anomaly, inviting the expert to advise as to the correct data and then being able to prove he had chosen the wrong one. Two identical time markers with two wildly different location points were shown in the data and he went with one on the basis that it appeared to fit with a further 10 other location points in an apparent sequence appearing to show a journey around a nearby location. He was not to know that additional evidence – numerous eye-witnesses and a recording of a 999 call proved the user of the phone did not go on a journey but remained static at the side of the victim doing CPR. On being supplied with this evidence the expert actually struggled to accept it and finally on doing so struggled to find a relevant explanation for a phenomenon that out lied his statistical modelling – he suggested a phenomena whereby nearby cars reflect the signal off each other and interfere with the data (in this instance there were no cars nearby).  This demonstrated the data was not infallible and expert evidence interpreting the data was not always able to remedy the problems inherent in the data.

In like cases those defending would be well advised to instruct someone with expertise in both GNSS and analysing phone data who then have the necessary knowledge to look at the location data along with what else the phone is doing and thereby establish the extent of the anomalies likely to be uncovered.


The Defendant was acquitted.


Reporting on the case can be found here.



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