Date: Aug 1, 2026

Pool Findings Are a Last Resort Where Only Two Possible Perpetrators Exist: “Binary” Attribution, Wider-Canvas Evaluation, and Forensic Imbalance

1) Introduction

In Re B (A Child: Uncertain Perpetrator) [2026] EWCA Civ 1024, the Court of Appeal (Civil Division) allowed an appeal by the mother against a Family Court “pool finding” that there was a real possibility she had inflicted three areas of bruising on her young child. The fact-finding trial (before HHJ Richard Case, reported at [2026] EWFC 103(B)) produced extensive and unchallenged findings that the intervenor (the mother’s former partner) had deliberately inflicted multiple serious injuries (including fractures) on numerous occasions.

The appeal was confined to the judge’s decision to place the three disputed bruises (groin, left ear, right hip/abrasion) in a pool of perpetrators (mother and intervenor) rather than attributing them to the intervenor on the balance of probabilities. The Court of Appeal held that, in the circumstances of this case, a pool finding was not rationally sustainable and substituted findings that the intervenor inflicted the bruising.

Key issues

Attribution: where only two possible perpetrators exist, when should the court make a positive finding (balance of probabilities) rather than a pool finding?
Method: whether the trial judge properly “surveyed the evidence as a whole” and compared the probabilities for each alleged perpetrator.
Fairness / forensic imbalance: how to avoid distorted conclusions where one party (here, the intervenor) withdrew from oral evidence and could not be fully cross-examined.
Appellate restraint: whether the pool finding was within the permissible range, applying the approach in Volpi v Volpi.

2) Summary of the Judgment

The Court of Appeal (Peter Jackson LJ, with whom Newey LJ and Falk LJ agreed) allowed the mother’s appeal. It set aside the Family Court’s pool findings for the three bruising injuries and substituted findings that, on the balance of probabilities, the intervenor inflicted those bruises as well. The case was remitted to the trial judge for welfare decisions on the basis of the findings as amended.

3) Analysis

A. The precedents and materials cited—and how they shaped the decision

Re B (A Child) [2018] EWCA Civ 2127: cited as part of the modern appellate framework on uncertainty and perpetrator identification in child protection fact-finding. In this appeal it formed part of the judge’s correct legal “self-direction” (not the point of departure), while the error lay in application.
Re B (Children: Uncertain Perpetrator) [2019] EWCA Civ 575; [2019] 1 W.L.R. 4440; [2019] 3 All E.R. 481: central to two strands of the Court of Appeal’s reasoning: (i) the need to seek to identify the perpetrator on the balance of probabilities before resorting to a pool; and (ii) the warning (at [51]) that where there is an imbalance of information about possible perpetrators, courts must take particular care that the imbalance does not distort the assessment. That warning became highly relevant because the intervenor withdrew from oral evidence, leaving the mother’s evidence subjected to far greater forensic testing.
Re A (Children) (Pool of Perpetrators) [2022] EWCA Civ 1348; [2023] 1 W.L.R. 1743; [2023] 2 All E.R. 870; [2023] 1 F.L.R. 565: reinforced the disciplined approach to perpetrator findings and the circumstances in which a pool is (and is not) justified. The Court of Appeal treated the Family Court Practice summary (adopted by the trial judge) as the correct method, but found it had not been followed for the bruises.
Re Y, V and B (Fact-Finding: Perpetrator) [2024] EWCA Civ 1034; [2025] 1 F.L.R. 795: noted as a recent decision in the same doctrinal “vein”, indicating a consistent appellate trajectory: pool findings are exceptional and must be justified by evidential inability, not convenience.
Volpi v Volpi [2022] EWCA Civ 464; [2022] 4 WLR 48: relied on by the intervenor to emphasise appellate restraint. The Court of Appeal accepted the general approach (interfere only if findings are irrationally insupportable / outside the permissible range), but concluded the pool findings here were unsustainable because the judge did not perform the required comparative evaluation on the evidence as a whole.
Family Court Practice (quoted in the judgment): the Court of Appeal treated this as an accurate summary of governing approach: the court should survey the evidence as a whole, consider individuals separately and together, and compare probabilities; the right question is whether the evidence establishes that an individual probably caused the injury.

B. The Court of Appeal’s legal reasoning

1. “Binary” attribution when there are only two possible perpetrators

A core clarification in this decision is the Court’s explanation of how the balance of probabilities operates where the court has already found an injury was inflicted and only two individuals could be responsible. The Court stated that the question becomes binary: which of the two is more likely to have been responsible? If that question can be answered, the more likely of the two is (for fact-finding purposes) responsible.

This is contrasted with situations involving more than two possible perpetrators, where identifying the “likeliest” candidate can be unsafe because it may still fall short of establishing probability against any particular person.

2. Pool findings are a “fallback”, not a parallel track

The Court emphasised a structured sequence:

First, the court must seek to identify the perpetrator on the balance of probabilities using the evidence as a whole.
Only if the court cannot answer the question due to lack of reliable evidence (or genuinely equal balance, described as rare) should it fall back on a pool finding.

On the facts, the Court found there was no proper basis for the judge to “find himself in a state of uncertainty” about the bruises.

3. The “wider canvas” and comparative evaluation were missing for the bruises

The Court accepted the trial judge’s approach for the eight serious assault findings: he legitimately used findings about other injuries to support conclusions about an injury under consideration. The error was that, for the three bruises, the judge did the opposite—he assessed them almost in isolation, focusing largely on perceived inconsistencies in the mother’s accounts.

The Court identified a set of “compelling features” that demanded comparative evaluation and strongly pointed to the intervenor, including:

All injuries clustered in the period when the intervenor was in the home.
Multiple proven serious assaults on a very young child (described as showing “propensity to injure”).
Elements of cruelty and dishonesty in denial.
Temporal proximity to proven rib fractures and similarity of possible mechanisms (gripping/squeezing).
By contrast, no prior inflicted injury during extended periods of the child’s life in the mother’s sole care, and no findings that the mother inflicted any injury during the relationship.

The Court was careful to draw a line: deciding the bruises solely by propensity would be wrong. But so too was assessing the bruises “as if the other injuries had never happened” and treating mother and intervenor as though they were in evidential parity.

4. Inconsistencies are not, without more, a bridge to perpetration

The trial judge identified inconsistencies in the mother’s accounts of when she first saw bruising and how it came to attention. The Court of Appeal held that the judge did not explain why those inconsistencies supported a conclusion that the mother might have injured the child, rather than reflecting poor recall or confusion concerning relatively minor injuries being examined long after events. Critically, the judge did not explain why these inconsistencies could outweigh the powerful inferences arising from the broader findings against the intervenor.

5. Forensic imbalance when a party cannot be cross-examined

The intervenor began but did not complete oral evidence and was not available for full cross-examination. The Court held that, in this context, the judge did not sufficiently adjust to the forensic imbalance: the mother’s evidence was scrutinised in detail while the intervenor’s account of these bruises “was not interrogated at all”. Applying the principle reflected in Re B (Children: Uncertain Perpetrator) [2019] EWCA Civ 575 at [51], the Court found the judge should have exercised caution before reaching adverse conclusions based largely on the mother’s evidence in these circumstances.

6. Appellate intervention and substitution (not rehearing)

Although the Court acknowledged the general appellate restraint in Volpi v Volpi, it concluded the pool findings were “simply unsustainable”. It substituted findings rather than ordering a rehearing because it regarded the proper conclusion as clear on the record: the bruises were, on the balance of probabilities, inflicted by the intervenor.

C. Impact

Sharper discipline on pool findings in two-perpetrator cases: this decision will likely be cited for the proposition that, once inflicted injury is established and there are only two possible perpetrators, the court should ordinarily be able to reach a probabilistic conclusion unless evidential inability is genuinely demonstrated.
Reinforced need for “wider canvas” reasoning: courts must show they have evaluated the full matrix—timelines, patterns, mechanisms, credibility findings, and established conduct—when attributing injuries.
Operationalising “forensic imbalance”: the judgment underscores that imbalance is not merely a procedural observation; it must influence evaluative caution, especially where one party’s account cannot be tested.
Welfare-stage consequences: the Court accepted (as did the permission decision) that even “lesser” injuries can materially affect welfare decisions; hence accuracy in attribution matters.

4) Complex concepts simplified

Balance of probabilities: The civil standard: the court decides a fact is true if it is more likely than not (i.e., >50% likely).
Pool finding / pool of perpetrators: A finding used when the court decides an injury was inflicted but cannot identify who did it. The court then identifies a “pool” of people who might have caused it (e.g., two carers). This can have major consequences because it may leave an innocent person under a cloud of suspicion.
Binary attribution: Where there are only two possible perpetrators, the fact-finding question becomes: which one is more likely responsible? If one is more likely, the court should usually make a positive finding against that person rather than defaulting to a pool.
Wider canvas: The full evidential context: patterns of injuries, timing, mechanisms, established conduct, credibility, and surrounding circumstances. Courts should not treat each injury as an isolated “mini-case” when the overall pattern strongly points in one direction.
Forensic imbalance: An unevenness in how evidence can be tested (e.g., one person gives full evidence and is cross-examined; another cannot be). Courts must take care that this does not unfairly skew findings against the person whose evidence is more fully examined.
Propensity: Evidence that someone has behaved a certain way before (e.g., inflicted injuries) can support inferences, but a finding must not be made on propensity alone; it must be grounded in the totality of evidence.

5) Conclusion

Re B (A Child: Uncertain Perpetrator) [2026] EWCA Civ 1024 reinforces that identifying a perpetrator on the balance of probabilities is the court’s primary task in inflicted-injury fact-finding. Where an injury is found to be inflicted and there are only two possible perpetrators, the court should ordinarily determine which is more likely responsible, rather than resorting to a pool finding, unless a genuine evidential impasse is demonstrated. The decision also highlights the practical importance of guarding against distorted reasoning where a forensic imbalance prevents full testing of one party’s account.