IQ Legal Training AlphabiolabsBerkeley Lifford Hall Accountancy Services

Home > Judgments > 2012 archive

Bristol City Council v A and A and Others [2012] EWHC 2548 (FAM)

Care proceedings in which contradictory hair strand tests for drug use arose – Court’s endorsement of principles relating to hair strand testing but declining to provide further guidance or enquire as to the causes of mistakes in the case.

In the course of care proceedings an issue arose as to the mother's drug use. She undertook hair strand testing carried out by Trimega Laboratories Ltd on a sample of hair taken in June 2011. The results showed increasing levels of opiate and cocaine use right up to the date of the taking of the sample. The mother vehemently disputed the results and was permitted to have a second test, performed on a sample of hair taken at the same time as the original one, this time to be undertaken by Concateno Cardiff Ltd (also known as Tricotech). The second results appeared to confirm the mother's account of not having taken drugs for the previous four months.

A hearing was listed to determine the reliability of the hair strand tests and the conclusions the court should draw in respect of the mother's drug use, as well as to consider the setting out of guidance for the use, interpretation of, and reliance upon, hair strand testing for drug use.

In the event the first two issues were resolved because Trimega conceded that its results were erroneous. Its case was this was down to an error in the process by which the sample was collected (although this was not accepted by Concateno).

The Court accepted that the mother had been abstinent from drugs for the five months prior to the hearing.

The Court endorsed the following propositions, which were agreed by both interveners:

(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.

Beyond the above, the Court did not see deem it necessary to provide detailed guidance, or embark upon any further investigation of the causes of the error by Trimega. Baker J held that these care proceedings were not the appropriate forum for such an enquiry and it would not be appropriate or proportionate to direct the court's limited resources to such an inquiry. He concluded by emphasising that in appropriate circumstances the family justice system continues to require expert evidence and that erroneous evidence can lead to grave miscarriages of justice.

Summary by Thomas Dudley, barrister, 1 Garden Court Family Law Chambers


Neutral Citation Number: 2012EWHC 2548(FAM)

Case No: DX11C00020



Royal Courts of Justice
Strand, London, WC2A 2LL

Date: 25/09/2012

Before :

- - - - - - - - - - - - - - - - - - - - -
Between :

Bristol City Council Applicant

 - and - 

A Mother 1st Respondent


A Father
2nd Respondent


SB and CB
(Minors, by their Children's Guardian)
3rd and 4th Respondents


1st Intervener


2nd Intervener
- - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - -
Robin Tolson QC (instructed by Wragge and Co) on behalf of the 1st Intervener
Piers Pressdee QC (instructed by Hanne and Co) on behalf of the 2nd Intervener
The other parties were not represented on the issue determined in this judgment


- - - - - - - - - - - - - - - - - - - - -
Approved Judgment
I direct that pursuant to CPR PD 39A para 6.1 no official shorthand note shall be taken of this Judgment and that copies of this version as handed down may be treated as authentic.


This judgment is being handed down in private on 25th September 2012. It consists of 15 pages and has been signed and dated by the judge.  The judge hereby gives leave for it to be reported.

 The judgment is being distributed on the strict understanding that in any report no person other than the advocates or the solicitors instructing them (and other persons identified by name in the judgment itself) may be identified by name or location and that in particular the anonymity of the children and the adult members of their family must be strictly preserved.

Mr. Justice Baker
1. This judgment considers a subsidiary issue that has arisen in care proceedings brought by Bristol City Council in respect of two children, SB and CB aged 4 and 3 respectively. Unusually, it is unnecessary to set out the family history that led to the proceedings. Suffice it to say that a major issue in the proceedings was the mother's drug-taking and its impact on her capacity to care for the children. She therefore underwent hair-strand testing carried out in June 2011 by the 2nd Intervener, Trimega Laboratories Ltd ("Trimega"). The results purported to show that the mother had been using increasing amounts of cocaine and opiates right up to the date of the sample being taken. The mother, however, vehemently denied that this was the case, and she was therefore given permission to obtain a second analysis on a sample taken at the same time. The results of the second test, carried out by Concateno Cardiff Ltd, (also known as TrichoTech but hereafter referred to as "Concateno") appeared to confirm the mother's version that that she had not used drugs as described or at all for approximately the previous four months.

2. Faced with this stark conflict of expert evidence, the proceedings were transferred to the High Court and listed for directions in October 2011 before me as Family Division Liaison Judge for the Western Circuit. In view of the local authority's understandable view of the impact of the mother's drug habit on her capacity to care for the children, I directed a hearing to resolve the conflict of evidence before any decision could be taken as to the long-term future of the family. Furthermore, the evidence appeared to raise questions as to the utilisation of hair-strand testing to detect drug use. Accordingly, both Concateno and Trimega were given permission to intervene in the proceedings. In view of the potential importance of the issues, I directed that the hearing be listed before the President of the Family Division, Sir Nicholas Wall, who had coincidentally arranged to sit in Bristol later that term.

3. The specific issues listed before the President were as follows:

(1) Which of the drugs tests on the mother's hair sample provides accurate and reliable evidence:

(a) Trimega only;
(b) Concateno only;
(c) both Trimega and Concateno; or
(d) neither?

(2) In the light of the court's answers to question 1, what findings should the court make in relation to the mother's drug use?

(3) What general guidance, if any, should be given to family courts about the use and interpretation of, and reliance upon, hair testing in the light of the apparent inconsistencies in the testing results provided by the two companies?  Does hair testing remain a reliable method for determining drug use in family courts?

4. At a further hearing on 14th November 2011 I provided that, whilst the case remained in the list before the President for the determination of the first two issues, "the question of whether and, if so, when any other issues arising therefrom, including the third issue … shall be determined will be considered by the President at [that] hearing." 

5. The reason for including the third issue was that, at the time of the directions hearings before me, there was no clear explanation for the diametrically opposite conclusions of the two reports. It was plainly possible that the explanation lay in a straightforward error. On the other hand, it was suggested by the parties to the care proceedings, and accepted by the court, that the explanation may involve a systemic problem with hair-strand drug testing.

6. In the event, and after a considerable amount of time and effort had been expended by the interveners in preparing for the hearing, it was conceded by Trimega shortly prior to the start of the hearing before the President that its analysis was erroneous and unreliable. The precise error was, and remains, unclear. Trimega said (although this is not accepted by Concateno) that it was believed that there had been an error in the process by which the hair sample was collected. The first issue was therefore resolved by an agreement placed before the President on the first morning of the hearing and recited as follows in the eventual order made at the conclusion of that hearing:

"AND UPON it being agreed between the First and Second Interveners that:

1. The Second Intervener accepts that a human error (believed by the Second Intervener to be in the collection process) has occurred in the production of its hair strand test results in this particular case;
2. The answer to Issue 1 therefore is (b);
3. The Second Intervener will produce a report, to be filed and served in these proceedings by no later than 1 March 2012, setting out:

(a) as definitively as they can, the nature and source of that human error; and
(b) the steps that they have taken to avoid the risk of such human error recurring in other cases; and

4. The Second Intervener will pay the costs of the First Intervener to be assessed if not agreed."

7. As a result of this agreement, the second issue was also resolved without a contested hearing.  The Court accepted that the scientific evidence demonstrated that the mother had used class A drugs until early 2011 but had been abstinent for five months prior to the hearing. As a result, the Court directed a community-based assessment under s.38 (6). The President listed the case for an issues resolution hearing before me on 15th March 2012. Although it is unnecessary to set out subsequent events in detail, it is worth pointing out that the assessment was positive, that the mother remains abstinent and is continuing to make progress, and that there is cautious optimism that she will be able to care for the children in the community.

8. The order of the President of 24th November 2011 made no reference to the third issue.  It did not list it as an issue to be considered at the IRH on 15th March or further within these proceedings. I am told that, during oral discussion, the President indicated that he would adjourn that issue generally and leave it to whoever took on the case as to whether they chose to deal with it.  Leading Counsel for the two interveners identified four propositions about which there was full agreement, and suggested that these could be incorporated in the President's judgment by way of resolution of the third issue, should the President see fit. In the event, the President did not take that course.

9. The interveners were not required to attend the IRH before me on 15th March, but by that date a report had been filed on behalf of Trimega in accordance with the agreement recited in the President's order of 14th November. In addition, a skeleton argument from Mr. Robin Tolson QC on behalf of Concateno was filed shortly before the hearing, addressing what were described as the "inadequacies" of the Trimega report, making further criticisms of Trimega's work on this case, and suggesting general guidance that might be given by the court. At that hearing, in addition to making directions for the welfare stage of the care proceedings, to which no reference is necessary in this judgment, I directed that the question whether the third issue as identified in my earlier order should be further considered by the court should itself be determined at a preliminary hearing; that the interveners should attend that hearing by counsel; that no other party need attend, save that the mother was permitted to attend by counsel; and that Trimega should file a position statement in response to the latest skeleton from Concateno. On 4th April, as a result of the points raised in Mr. Tolson's skeleton argument, I expanded the scope of the further hearing so that it would determine not merely whether the "third issue" left unresolved following the President's hearing should be further considered but also whether there should be a further inquiry into the actions of the Trimega experts. The hearing was listed on 28th May but, in the event, that fixture had to be aborted because of pressure of other work, and consequently it was agreed that the court would resolve the two preliminary issues on the basis of written submissions alone.

10. Those submissions are substantial in volume. Including the original skeleton arguments placed before the President, each intervener has filed four skeleton arguments or position statements. For this preliminary issue, Mr. Tolson's document filed in March and running to 15 pages and 36 paragraphs was met by a "position statement and skeleton argument" from Mr. Piers Pressdee QC on behalf of Trimega that extended to 47 pages, 124 paragraphs and 13,001 words. This was followed by a supplemental document from Mr. Tolson of a more modest size, but overall the effort expended by leading counsel on these two preliminary issues is very substantial. One wonders how voluminous their material would be, were I to direct a full hearing on the issues as proposed by Mr. Tolson.

11. I have carefully read all of their documents and I mean no disrespect for either counsel, or for their industry, in saying that it is neither necessary nor proportionate to set out their submissions in any detail in this judgment.  The answer to both preliminary issues is, in my judgment, straightforward.

12. Mr. Tolson's submissions can be summarised from his various documents as follows.

13. First, he contends that "Trimega's inadequacies risk belittling and damaging the reputation of this important testing and the companies carrying it out ….Trimega risk throwing out the industry's healthy baby with the bathwater that is Trimega's own".  He describes the report filed on behalf of Trimega to explain the error that occurred in this case as (inter alia) "a whitewash" and "inadequate", and submits that it "not only highlights glaringly flawed processes at Trimega but also exposes all previous allegedly independent expert reports filed on Trimega's behalf as themselves deeply flawed and … filed in plain breach of the duties imposed upon independent experts with family proceedings" as set out in Family Procedure Rules 2010 Practice Direction 25A. He says that the error has never been subject to scrutiny, that it should as a matter of law be tested and that "the system will have failed if it cannot be tested".

14. Secondly, he invites the court to endorse the four general propositions about the use of hair-strand testing for drugs which were agreed between the interveners at the hearing before the President and which he submits are uncontroversial. Those propositions are as follows.

(1) The science 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.

15. Thirdly, Mr.Tolson invites the court to consider giving more specific guidance, in particular that international standard ISO/IEC 17025:2005 provides "the gold standard" for laboratories carrying out tests of this kind and that formal laboratory accreditation to this standard provides assurance of quality that the standards are being met. He submits that guidance on the use of hair strand testing for drug use would be in the interests of the family justice system because it would complement the decision of Moylan J in Richmond LBC v B, W, B and CB [2010] EWHC 2903 (Fam), [2011] 1 FLR 1345 concerning hair strand tests for alcohol and remove confusion as between hair strand testing for alcohol and hair strand testing for drugs.

16. Mr. Pressdee's submissions in reply can be summarised thus. His first and principal argument is that any further consideration of either the "third issue" left unresolved by the President or the details of Trimega's error(s) is neither necessary nor appropriate, nor consistent with the overriding objective set out in para 1.2 of Family Procedure Rules Practice Direction 12A – Public Law Proceedings Guide to Case Management ("the Public Law Outline") which provides:

"(1) This Practice Direction has the overriding objective of enabling the court to deal with cases justly, having regard to the welfare issues involved. Dealing with a case justly includes, so far as is practicable:

(a) ensuring that it is dealt with expeditiously and fairly;
(b) dealing with the case in ways which are proportionate to the nature, importance and complexity of the issues;
(c) ensuring that the parties are on an equal footing;
(d) saving expense; and
(e) allotting to it an appropriate share of the court's resources, while taking into account the need to allot resources to other cases."

17. Mr Pressdee submits this overriding objective would not be served by extending the inquiry in the manner proposed by Concateno. He submits that, whilst it is often appropriate and helpful for courts to give guidance as to law and practice in family cases, such guidance normally arises as an adjunct to the court's decision rather than as a free-standing issue. When the hearing was listed before the President, there were possible resolutions of the first issue which might call into question the integrity of the science. Now that the first issue has been resolved by an admission of error by Trimega, no need for guidance arises. Through counsel, Trimega accepts "that it did not fully or accurately investigate the reason for the difference between its test results and those of the First Intervener when first called upon to do so", and that "initially it focused disproportionately on the aspects of the evidence that it felt supported its position and undermined that of the First Intervener, and that it was not as swift as it should have been to appreciate the contrary evidence and the wider picture." Mr Pressdee further informs the court that Trimega "has, following wide-ranging review of its service, instituted a large number of changes geared to improve the service that it provides and to ensure that errors of the kind that occurred in this case are not replicated in others."  Later in his skeleton argument he gives detail of the changes that Trimega has introduced to its collection and other processes. He therefore argues that a finding as to the actual source of Trimega's error is not necessary to resolve any threshold, assessment or welfare issue concerning the subject children.

18. Secondly, Mr. Pressdee points out that any guidance that the court may give affects not just the interveners but every other drugs company offering or looking to offer a hair strand drugs testing service to family courts.  As a matter of essential fairness they would have to be given the opportunity to comment on any guidance contemplated and/or to formulate and suggest guidance of their own.

19. Thirdly, Mr. Pressdee refutes Mr.Tolson's criticism of the report filed by Trimega, and submits that the primary motivation of Concateno is to obtain a judgment critical of Trimega, and guidance from the court, that could be used for commercial advantage. "For all the rather pious talk of standing up for the industry, the evidence of a company acting to further its own self-interest is pretty plain to see." There are further references to commercial factors later in the skeleton argument. For example, through counsel Trimega acknowledges "that it should have apologised to the court and to the mother for failing to deliver an accurate and reliable service in this case". Mr. Pressdee adds, however, that "but for the presence of its major commercial rival at court, ready to extract the greatest commercial advantage out of any such apology, it would have done".

20. Mr Pressdee's skeleton concludes with this peroration: "The issue in the proceedings that fell to be resolved for their determination, warranting the involvement of the interveners, has long since been resolved.  The focus of the court must now properly and exclusively be on the subject children.  This is a care case.  It is not some public enquiry."

21. I accept Mr. Pressdee's submission that the starting point is the overriding objective in para 1.2 of PD12A. The three specific questions which arise are whether the proposed hearing would (1) deal with the case justly, having regard to the welfare issues involved; (2) deal with the case in a way that is proportionate to the nature, importance and complexity of the issues and (3) allot to the case an appropriate share of the court's resources.

22. As Mr Pressdee surmises, the reason for including the third issue on the agenda for consideration by the President, and for giving the two companies permission to intervene in the proceedings, was the possibility that the discrepancy between the test results provided by Trimega and Concateno was attributable to flaws in the science and therefore called into question the validity of hair testing for drugs. In the event, the reason for the discrepancy is now accepted as being human error on the part of one of the companies, Trimega. The integrity of the science, and the validity of hair strand testing for drugs, is unaffected by this case. There is, therefore, no proven need for a general inquiry into the matter, or for detailed guidance as to how such tests should be carried out or used in court proceedings.

23. Furthermore, I agree with Mr. Pressdee's submission that this court is not the appropriate forum for any such inquiry. The jurisdiction of the family courts is to determine specific disputes about specific families. It is not to conduct general inquiries into general issues. Occasionally, a specific case may demonstrate the need for general guidance, but the court must be circumspect about giving it, confining itself to instances where it is satisfied that the circumstances genuinely warrant the need for such guidance and, importantly, that is fully briefed and equipped to provide it.

24. The arguments advanced in this case have been littered with references to commercial factors.  I have already referred to Mr. Pressdee's frank assertion that Trimega had withheld an apology to the mother because it feared that its rival would exploit such an apology for commercial advantage. In this respect, Trimega's attitude does no credit to an organisation entrusted with the responsibility of providing independent expert advice to the court on matters that will affect the lives of children and families. In his final document, Mr. Tolson on behalf of Concateno frankly acknowledged that "ultimately … both companies have commercial interests in this case which are entirely legitimate". In circumstances where both interveners admit to commercial motivation, the court cannot be confident that would have all the information at its disposal to provide clear, detailed and objective guidance. Any process designed to provide such detailed guidance would have to allow other interested parties to make representations.

25. There is agreement amongst the interveners as to the four uncontroversial propositions advanced by Mr. Tolson. The court endorses those propositions which, for ease of reference, I repeat here:

(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.

26. For the reasons set out above, however, I decline to sanction any extension of this court process to lead to the promulgation of any more detailed guidance. Such a course would be unnecessary and disproportionate.

27. I am equally unpersuaded that it would be appropriate or proportionate to allow any further share of the court's limited resources to continue the inquiry into the nature of Trimega's error. Mr. Tolson describes the report prepared following the hearing before the President as a "whitewash" and accuses Trimega of falsely asserting that the error lay in the collection process to conceal more fundamental flaws in their systems. He sets out the justification for that assertion in considerable detail. Mr. Pressdee denies this allegation and goes into even more extensive detail as to the investigation carried out by Trimega into the cause of the human error in this case. In order to investigate those matters, fully and fairly, the court would in my judgment have to conduct a hearing lasting several days, summoning several witnesses from Trimega for oral evidence, and in all probability commissioning further independent expert evidence. At the conclusion of such a hearing, the court might give a judgment setting out its findings, but no order would follow.

28. I do not regard this court in these proceedings as the appropriate forum for the investigation of these matters. I accept Mr. Pressdee's submission that the court must be guided by the overriding objective as set out in para 1.2 of PD12A. In my judgment a hearing for the purposes of giving guidance, or investigating the nature of Trimega's error in this case, would be disproportionate and an inappropriate use of the court's resources, given the enormous demands on the time of judges of the Family Division.

29. Each intervener makes representations that the other should meet a proportion of its costs in connection with the hearings since November 2011. Trimega were ordered by consent to pay Concateno's costs up to and including that hearing. In my judgment, no further order for costs is appropriate. It was the court that, for reasons explained above, raised the question whether guidance should be given. The court has now concluded that no such guidance is needed beyond the agreed points set above. It was the court that directed Trimega to investigate and report on its error. Having read that report, the court has concluded that any further inquiry by this court would be disproportionate and inappropriate. Neither of these decisions warrants any further costs penalty.

30. 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.