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Guidance given in important hair strand testing judgment

Practices of testers affirmed and suggestions made for report writing

Mr Justice Peter Jackson has affirmed the existing practices of providers of hair strand tests for cocaine and has offered suggestions as to how reports might be written.

In H (A Child: Hair Strand Testing) [2017] EWFC 64 Peter Jackson J (as he was at the time of handing down judgment) also questions whether, in retrospect, the evidence of 'ostensibly positive' hair strand test results supporting very low level or infrequent drug use at interim removal stage was in truth sufficient to justify the removal of a baby at birth when balanced against the other evidence supporting no use. The judgment is therefore of importance to all practising in this area of family law.

The key factual dispute in the case related to the mother's use of cocaine. Many tests had been conducted on the mother's hair over a two-year period, as well as her having been (for some of the time) subjected to much more regular urine testing. When it came to interpreting the HST results, the witnesses from the testing organisations gave the opinion that they were likely to result from the active use of cocaine, rather than from external contamination. The exception to this was that one witness did not reach this conclusion in relation to the 2017 results because of their lower levels.

The judgment concludes that the variability of findings from hair strand testing does not call in to question the underlying science but underlines the need to treat numerical data with proper caution.

When considering the writing of reports, His Lordship notes that

"[T]he writer [of a report] must make sure as far as possible that the true significance of the data is explained in a way that reduces the risk of it becoming lost in translation. The reader must take care to understand what is being read, and not jump to a conclusion about drug or alcohol use without understanding the significance of the data and its place in the overall evidence."

His suggestions are set out at paras 57 to 59 of the judgment.

For an article – written by Emily James and Kate Tompkins, both from 36 Family, who appeared in the case – explaining the several issues addressed by the judgment, click here. For the judgment itself, prefaced by a summary, written by Millicent Benson, of 1 King's Bench Walk, click here.

15/10/17