The Supreme Court has allowed R.K.’s appeal and quashed his convictions for causing serious harm by infecting two women with HIV. The Court found that the jury needed clearer guidance on the complainants’ evidence and the limits of the scientific evidence presented at trial. It did not decide whether the verdicts were perverse.
R.K. was convicted in 2018 on two counts under section 4 of the Non-Fatal Offences Against the Person Act 1997 and sentenced to 10 years’ imprisonment on each count. The Court of Appeal upheld the convictions in 2022. The Supreme Court’s judgment, delivered by Ms Justice Iseult O’Malley on 14 December 2023, concerned the appeal from those decisions.
The prosecution alleged that R.K. knowingly or recklessly infected Ms K and Ms C through unprotected sexual intercourse, while knowing he had HIV. The central issue was whether he had transmitted the virus to them. The prosecution relied mainly on the women’s accounts that they had unprotected sex with R.K. and not with other partners. Both disclosed additional sexual relationships during cross-examination, after initially giving more limited accounts.
The medical and laboratory evidence did not establish who transmitted the virus. The treating consultant, Dr John Lambert, believed R.K. had infected the women, but the Supreme Court said his opinion relied partly on sexual histories that later proved incomplete and on a mistaken understanding of the virus subtype. The laboratory analysis was designed to inform treatment, not trace infection. The experts agreed it could not confirm transmission; the defence expert said the available data was inadequate for forensic conclusions and showed differences that could point away from a common source.
The Court said the prosecution had to prove beyond reasonable doubt that there was no other reasonably possible source of infection. The defence did not have to produce evidence identifying another source. The women’s accuracy about their sexual histories was therefore central. The jury should have been told that they could not convict unless they accepted beyond reasonable doubt that the women were fully truthful and accurate when they said they had never had unprotected sex with anyone else.
The jury also asked whether all three people had a particular viral mutation and how likely it was to have come from a fourth person. The trial judge confirmed the mutation was present but said the further question could not be answered from the evidence. The Supreme Court held that the judge should have explained that the experts saw no probative value in the mutation evidence and that the analysis could not establish transmission.
The Court allowed the appeal and quashed both convictions. It did not rule that phylogenetic analysis is required in every prosecution of this kind; it said the necessary evidence depends on the case and that, without strong scientific evidence, particular care is needed with the factual evidence excluding other possible sources.