Bristol City Council v A Mother & Ors

Family proceedings are concerned with resolving disputes about the particular family before the court. They are not ordinarily a forum for general inquiries into wider scientific, professional or commercial issues. General guidance should be given only where the case genuinely demonstrates a need for it and the court is properly briefed and equipped to provide it. The overriding objective requires proportionality, fairness, expedition and an appropriate allocation of judicial resources. Where an apparent conflict in expert evidence is resolved by an admitted human error, a further inquiry or detailed guidance may be unnecessary and disproportionate. Hair-strand testing for drugs was nevertheless recognised as an established and non-controversial science, subject to careful interpretation of positive results, sequential testing and drug quantities.

This was a subsidiary issue arising in care proceedings concerning two children. Conflicting hair-strand drug-test results had initially raised questions about the reliability of the testing, the cause of the discrepancy, and whether general guidance should be issued to family courts.

The discrepancy was resolved when Trimega Laboratories Ltd accepted that human error had occurred and that its results were unreliable. The remaining questions were whether the court should conduct a general inquiry or issue more detailed guidance about drug testing, and whether it should investigate further the precise nature of Trimega’s error.

1. The court applied the overriding objective in para 1.2 of Family Procedure Rules Practice Direction 12A – Public Law Proceedings Guide to Case Management. The relevant questions were whether the proposed hearing would deal with the case justly having regard to the welfare issues, whether it was proportionate to the nature, importance and complexity of the issues, and whether it would make an appropriate use of Family Division resources.
2. The scientific discrepancy did not establish any systemic flaw. It had been accepted that the discrepancy resulted from human error by one company. The integrity of hair-strand testing for drugs was therefore unaffected. There was no proven need for a general inquiry or detailed guidance.
3. Family courts determine specific disputes concerning specific families. They should be circumspect about giving general guidance, doing so only where the circumstances genuinely warrant it and where the court is fully briefed and equipped to provide it. Commercial interests affecting the interveners meant that the court could not be confident that it had all the information required for objective guidance.
4. The court endorsed four agreed propositions: the science of hair-strand drug testing is well established and non-controversial; a positive identification above the cut-off level reliably shows exposure; sequential testing is a good guide to the pattern of use; and the quantity detected is not proof of the quantity used, although it is a good guide to relative levels of use over time.
5. A further hearing to investigate the precise error would have required several days, oral evidence and potentially further expert evidence, but would have produced no consequential order. It was therefore disproportionate and an inappropriate use of court resources. No further costs order was made.
6. The judgment’s wider observations emphasised that appropriate expert evidence remains essential in family proceedings. The court referred to Re JS [2012] EWHC 1370 (Fam) and stated that hair-strand testing satisfied the relevant criteria for expert evidence in this case.

First-instance judgment in care proceedings. The judgment describes earlier directions and hearings before the President of the Family Division, but no appellate history is stated.