Arshad, R. v

Where a prosecution depends fundamentally on expert medical evidence in an area of acknowledged scientific uncertainty, the summing-up must make clear that the jury may convict only if sure of the prosecution case after giving full weight to alternative and unknown causes.

The directions need not employ prescribed expressions such as special caution or unknown cause. It is sufficient if, read as a whole, they fairly present the competing expert evidence, the limits of medical knowledge, and the need to exclude realistic alternatives before conviction.

The appellant was tried at the Crown Court at Luton for the death of her 13-week-old son. At the close of the prosecution case, the judge directed her acquittal of murder. The jury convicted her of manslaughter and she received a suspended sentence.

The prosecution relied on expert evidence concerning brain injury, subdural haemorrhage and retinal haemorrhages. The defence advanced possible natural or non-inflicted explanations and challenged the significance of the medical findings.

On appeal, the sole issue was whether the judge’s summing-up complied with the guidance in R v Henderson [2010] EWCA Crim 1269, particularly concerning uncertain medical science and the realistic possibility of an unknown cause.

1. Appeal dismissed. The conviction for manslaughter was safe.
2. In a case in which expert evidence is fundamental and medical science is uncertain, the jury must be directed so that they understand they cannot convict unless sure that the prosecution has proved the alleged cause. The direction must ensure that realistic alternative and unknown causes are not overlooked.
3. The guidance in R v Henderson [2010] EWCA Crim 1269 does not require the judge to use particular words. It is enough that the summing-up, taken as a whole, makes the need for caution and the possibility of unknown causes clear in substance.
4. The trial judge fairly identified the competing expert evidence. He explained the uncertainty surrounding aspects of the medical evidence, including possible causes of spinal nerve-root damage and retinal haemorrhages. He also reminded the jury of the possibility of alternative and unknown causes.
5. The judge gave adequate directions on evaluating conflicting experts. The jury were told to assess the evidence by reasoning rather than by an expert’s reputation or institutional affiliation. They could therefore be in no doubt that they had to exclude other realistic explanations before finding that the appellant had caused the death in the manner alleged.

• Court of Appeal (Criminal Division)—the appeal against conviction was dismissed: [2012] EWCA Crim 18.
• Crown Court at Luton—following a directed acquittal on murder, the appellant was convicted of manslaughter and received a suspended sentence.