This case, to be heard on Wednesday and Thursday this week, will give the Supreme Court the welcome opportunity to re-visit, in the context of a non-accidental injury in public law Children Act proceedings, the ‘uncertain perpetrator’ cases – ie those cases where the ‘pool’ of those of whom it can be said that there is a realistic possibility that they harmed the child can be defined, but within that pool it is not possible, on the balance of probabilities, to attribute responsibility.

The case concerned findings made following serious injuries to a one-month-old child in 2007. The findings, in April 2008, were to the effect that both parents remained within the pool of possible perpetrators. The father had played no role in the proceedings and the judge commented that there remained ‘a high index of suspicion’ in relation to him. However, for a number of reasons she did not accept that the mother could be excluded from the pool of possible perpetrators. Subsequently, at the parties’ joint request and apparently to assist the team of experts who were about to carry out an assessment of the mother, the Judge agreed to develop her findings by indicating the relative suspicion she attached to each parent, and did so, saying that she considered the father to be ‘60% likely’ to have caused the injuries, and the mother ‘40%’. She refused the mother’s subsequent request to be excluded from the pool altogether on the basis that in the context of a balance of probabilities approach (as re-affirmed by the House of Lords in Re B [2008] UKHL 35; [2008] 2 FLR 141 – for which see below),  for the mother to be ‘40% likely’ to have caused the injuries meant that she did not cause them. This refusal was the subject of the unsuccessful appeal to the Court of Appeal.

The ‘uncertain perpetrator’ cases have always sat uneasily within the chain of cases dealing with the standard of proof to be applied in cases of serious non-accidental injury to a child. The leading case, Re O and N [2003] UKHL 18; [2003] 1 FLR 1169 considered whether, in a case where it was not possible to determine which of two or more individuals was responsible for an injury, this meant that each must on the balance of probabilities be exonerated, the threshold criteria in CA 1989, s 31(2) found not to be met, and the state’s powers to intervene curtailed. Lord Nicholls said in answer to this suggestion that:

‘Here, as a matter of legal policy, the position seems to me straightforward. Quite simply, it would be grotesque if such a case had to proceed at the welfare stage on the footing that, because neither parent, considered individually, has been proved to be the perpetrator, therefore the child is not at risk from either of them.’ (para 27)

This decision, perfectly understandable from every practical and policy-driven point of view, has caused enormous difficulties when it is sought to reconcile it with the leading cases on non-accidental injuries generally and the standard of proof. The tension came to a head last summer with the House of Lords’ decision in the case of Re B [2008] UKHL 35; [2008] 2 FLR 141. This decision swept away all jurisprudence to the effect that a different approach might be taken to the civil standard of proof in serious non-accidental injury cases, and set out a very clear ‘binary’ approach: each allegation, whatever its nature, is to be tested on the balance of probabilities. Either it is found proved or it is not. There is no middle way.

The mother in Re S-B submitted that this meant Re O and N must be overruled, by implication although clearly not expressly. Applying the binary approach in Re S-B, where the Judge had actually differentiated between the two possible perpetrators, a mother found ‘40% likely’ to have caused the injuries did not cause them.

The Court of Appeal disagreed. Thorpe LJ, giving the leading judgment, pressed the mother’s counsel to accept that this approach would mean that the only true ‘uncertain perpetrator’ cases would be those where the judge was unable to go further than a finding that each perpetrator was equally likely to have been responsible for the injury. If there was even a 51%/ 49% attribution of likely responsibility, the person found to be less likely to have been responsible would have to be exonerated. He commented that the Judge (who amplified her judgment before the House of Lords gave its decision in Re B) would have been wiser, with hindsight, to have declined the invitation to indicate her views as to the relative likelihood of each parent having been responsible.

The consequences of that approach in all ‘uncertain perpetrator’ cases, however, will be that judges are likely to find themselves fettered in terms of the findings they make for fear of leaving the door open to further requests for exoneration. This is, it is suggested, an inevitable consequence of the ‘legal fiction’ created, for understandable policy reasons, by the decision in Re O and N, which has been stretched still further by the strict binary approach imposed by the House of Lords in Re B.

So there is plenty of scope for further clarification from the Supreme Court of the proper approach to the fact-finding exercise in ‘uncertain perpetrator’ cases. As an aside, it is hoped that the Court may give some guidance as to the position when the ‘pool’ includes a non-parent (perhaps a childminder or nanny.) If it is a realistic possibility that the perpetrator was a relative stranger, and also a realistic possibility that one of the child’s parents was responsible, how is this situation to be distinguished from that where it is not possible to say on the balance of probabilities that the injury itself was non-accidental? In other words can it really be said in these cases, particularly following Re B, that the s31(2) threshold criteria (harm attributable to the care being given to him… ‘not being that which it would be reasonable to expect a parent to give’) are met at all?

Madeleine Reardon practices in all areas of family law at 1KBW.  She has a particular interest in both public and private law children work. She is an update editor of Hershman and McFarlane: Children Law and Practice’.