Richard Ager comments on the case of Bristol City Council v A Mother and ors and the use of hair strand testing.

In Bristol City Council v A Mother & ors 2012 EWHC 2548 (Fam), Baker J was invited by the two main hair strand testing companies (Trimega and Concateno – the latter is usually referred to as Trichotech) to rule on the propriety of their respective procedures.

On the facts of the case, the Mother had given a sample for hair strand testing for drugs use to Trimega. They reported that she had used drugs in the relevant period which lead to her continuing care of her child being questioned. The Mother absolutely denied drugs use in the relevant period and was given leave to have another sample, taken at the same time as the first, to be tested by Concateno. The outcome of that testing was that the Mother had not used drugs in the relevant period. The case was transferred to the High Court on the question of the outcome of the two drugs tests. The matter was listed before Sir Nicholas Wall, P, who heard that Trimega accepted that a human error had occurred in the taking of the sample and thus the result of the Concateno test stood. Happily, the Mother continues to do well and there is the prospect of her continuing to care for her child.

However, Concateno in their written submissions made criticisms of the processes of Trimega. Trimega did not apologise for their error fearing this might give a commercial advantage to their competitors. Both companies submissions were “littered” with commercial arguments which Baker J had no hesitation in saying would be disproportionate and an inefficient use of precious court time to resolve.

However, Baker J endorsed the following general propositions regarding hair strand testing:

  1. “The science involved in hair strand testing for drug use is now well-established and not controversial.
  2. A positive identification of a drug at a quantity above the cut-off level is reliable as evidence that the donor has been exposed to the drug in question.
  3. Sequential testing of sections is a good guide to the pattern of use revealed.
  4. The quantity of drug in any given section is not proof of the quantity actually used in that period but is a good guide to the relative level of use (low, medium, high) over time.”

This then resolves (or should resolve any controversy about hair strand testing for drug use.

However, the Judge went on to say:

“Lest it be thought that this case diminishes the importance of expert evidence in family cases, I conclude by emphasising again that in appropriate circumstances the family justice system requires, and will continue to require, expert evidence to ensure that it makes the right decisions about the future of children. I repeat what I said in Re JS [2012] EWHC 1370 (Fam) at para 47:

“Whilst the courts always have to be vigilant to guard against the proliferation of experts in family proceedings, the court must, in my judgment, always have available to it the necessary expertise to make the right findings in these important and difficult cases.”

As Ryder J has recently observed in “Judicial Proposals for the Modernisation of Family Justice” (July 2012) (at para 41):

“In every case, the judge should be able to say: is your expert necessary i.e. to what issue does the evidence go, is it relevant to the ultimate decision, is it proportionate, is the expertise out with the skill and expertise of the court and those already involved as witnesses by reference to the published and accepted research upon which they can rely and of which the court has knowledge.”

Plainly hair strand testing for drugs satisfies all of these criteria. But, as this case illustrates, a high degree of responsibility is entrusted to expert witnesses in family cases. Erroneous expert evidence may lead to the gravest miscarriage of justice imaginable – the wrongful removal of children from their families.”

This is a salutary reminder of the need for careful selection of appropriate experts in these very sensitive and difficult cases, the responsibility placed on those experts and the need for close scrutiny of their views.