Momentum builds for reform in hair strand testing practices

Since its establishment in 2009, Forensic Testing Service (FTS) has advocated an end to the use of Society of Hair Strand Testing cut-off levels in hair strand testing for the family courts. Our position on their use is outlined in these articles: one and two.

FTS has long been a lone voice in the industry speaking out against cut-offs, despite a sizeable body of case law and scientific evidence supporting our position. It is refreshing, then, to see how dramatically the conversation has shifted in the last year. The shortcomings of cut-offs in the family courts now seem to be much more widely understood and accepted.

Nowhere was this clearer than at the recent International Child Law Conference, held last month in Jersey. Keeley Lengthorn, Head of Public Law Children at RWK Goodman, and Doushka Krish, barrister at 1GC, gave an engaging presentation at the conference on the risks associated with relying on cut-offs.

They noted that hair strand testing is an evolving field, and although it plays an important role in family care proceedings, caution must be exercised when determining the evidential value of hair strand analysis. Results are never to be used in isolation or presented through an oversimplified summary. Experts must fully and faithfully explain their findings, as well as explain the significance of the data and its place in the overall evidence in an understandable way. Lengthorn and Krish reiterated much of what FTS has long been saying – that hair strand test results need to be considered as part of the wider evidential picture and not just seen in isolation as numbers.

They touched on four legal cases which are particularly helpful in understanding how the courts have determined hair strand testing evidence should be reported, instructed and assessed:

• London Borough of Richmond v B [2010] EWHC 2903 (Fam),

• R (A Child: Care Order)  [2017] EWHC 364 (Fam) (Hayden J),

• Re H (A Child: Hair Strand Testing) [2017] EWFC 64 [2018] 1 FLR 762  (Jackson J), and

• Re D (Children: Interim Care Order: Hair Strand Testing) [2024] EWCA Civ 498

In an industry that is in various ways self-regulating, many companies have a vested interest in continuing the use of cut-offs. As has been noted, using cut-offs enables testing to be quicker, cheaper and easier.

But the real cost of this is family justice – particularly if a false negative or false positive result is used to determine whether a child stays with or is removed from a parent. Results using cut-offs can often be more expensive for local authorities too, particularly if disputed results necessitate a second test or lead to cross-examination in court.

FTS turnaround times are not always the fastest in the sector and there is good reason for this – our expert interpretations factor in all findings, not just laboratory results above cut-off levels, and consider all possible relevant findings in our interpretation and conclusions. We provide expert opinion evidence and take a full forensic history of your client, which is factored into our interpretation. We always check that relevant influencing factors, such as a client’s hair colour, use of hair straighteners or dyes, ethnicity and pregnancy, have been fully considered. We also maintain a strict chain of evidence and fully document where hair samples have been taken from, given how significantly this can influence findings. It takes time to gather evidence properly, but those extra few hours can make all the difference. When it comes to cut-offs, as stated in Forensic Science International, we should “challenge this practice by arguing that choices made for convenience should not be to the detriment of balance and coherence.”

Change is often met with resistance, particularly by those with a vested interest in maintaining a system that appears to work well for them. Those providing hair strand testing need to prioritise getting the correct outcome for the child and family over business-as-usual attitudes. But it’s clear the tides are turning. FTS welcomes this with open arms.

We have been proud to support the Taking a Strand campaign, run by Birth Companions, 4PB and MSB, to change the way hair strand drug tests are often instructed and interpreted in the family courts. You can watch a recent webinar on the campaign here.

If you are interested in learning more about why cut-offs fail, check out our Resources page for helpful explainer videos and publications.