KN, R (on the application of) v London Borough of Barnett

Age disputes require the court first to assess the available evidence and determine the most likely age. The burden of proof is a fallback where the court cannot reach a conclusion by assessment. A local authority’s age assessment must adopt a holistic approach and give proper weight to relevant non-dental evidence. Reliance on dental development alone, particularly without acknowledging its substantial margin of error, may constitute an error of law. Assessments must also be procedurally fair and rational, with suitable expertise where the claimant is severely traumatised. Statistical methodologies used by experts should be treated cautiously unless scientifically established and subjected to proper peer review.

The claimant, a severely traumatised young woman trafficked from the Democratic Republic of Congo, challenged the London Borough of Barnett’s assessments that she was over 18. The first assessment relied substantially on a forensic dental report. A second assessment treated her physical appearance, demeanour, inconsistent accounts and available reports as indicating adulthood.

The claimant did not attend the fact-finding hearing or give evidence because of medical evidence concerning the risk of serious psychological harm. The court considered the evidence from the assessors, experts and other professionals, and had to determine her age and, if possible, her date of birth. The central issue was whether she was under 18 and therefore entitled to services under section 20 of the Children Act 1989.

1. Outcome. The court found that the claimant was under 18 and that her date of birth was 23 August 1993. The defendant therefore owed her a duty to provide services under section 20 of the Children Act 1989.
2. Assessment and burden of proof. The proper first step in an age-dispute is an assessment of all the evidence to determine the claimant’s age and, if possible, date of birth. The court should resort to the burden of proof only if the evidence does not permit a reliable assessment. Where a stark choice concerns credibility or the authenticity of documents, the claimant bears the burden of proving the relevant fact on the balance of probabilities. The approach in R(A) v LB Croydon [2009] UKSC 8 supported assessment rather than treating the case at the outset as a conventional balance-of-probabilities exercise.
3. Holistic assessment. A local authority must consider the evidence as a whole. Treating a dental assessment as establishing adulthood, without properly considering relevant non-dental information, was an error of law. The court applied the reasoning in The Queen on the application of A v Liverpool City Council [2007] EWHC 1477 (Admin) and the principles in R (B) v Merton [2003] EWHC 1689 (Admin).
4. Evidence and fairness. Dental development had a large margin of error and could not safely determine age in isolation. The second assessment was undermined by inadequate experience, insufficient expertise concerning traumatised and trafficked young people, unexplained reliance on adverse credibility and failure to demonstrate how the evidence supported the conclusion. On conventional judicial review grounds of procedural fairness and rationality, the assessment was open to being quashed.
5. Expert evidence. The court associated itself with the concerns expressed in The Queen on the application of R v The London Borough of Croydon [2011] EWHC 1473 (Admin) about Dr Birch’s qualifications and methodology. Her statistical methods were not scientifically established and had not undergone proper academic peer review. The court cautioned against relying on her in future age-assessment cases, although it had not needed to rely on her evidence in reaching its decision.