This case establishes that a conclusive grounds decision (CGD) by the Single Competent Authority (SCA) and the full minute of the decision (the reasons) are admissible in criminal proceedings.
In this case the Director of Public Prosecutions (DPP) appealed, by way of case stated, a decision by a District Judge, sitting at Wimbledon Youth Court, to acquit a 15 year old boy (M) of charges of possession of a bladed article, possession of a Class A drug (heroin) and possession of a Class A drug (cocaine) after he successfully raised a defence (of exploitation) pursuant to s.45 MSA 2015 (the statutory defence).
The issue of law for the High Court to determine was whether M discharged the evidential burden which lay on him in raising the statutory defence.
At trial M adduced both the CGD itself and the reasons for the SCA’s decision, made upon receipt and investigation of an NRM referral by M’s child social worker at Lambeth Social Services. The fact of the decision was adduced by way of an admission and the reasons for it as an exhibit.
On behalf of the DPP it was argued that the District Judge erred in relying on the SCA decision in criminal proceedings. In relation to the reasons for the CGD, the DPP argued that they are inadmissible due to being non-expert opinion evidence and hearsay.
Firstly, the Court held that expert evidence is admissible per se in relation to the issue of criminal exploitation:
‘Expert evidence is admissible when the subject matter is something on which the ordinary person without particular experience in the relevant area could not form a sound judgment without the assistance of a witness with such experience. The factors relevant to trafficking or exploitation are not necessarily within the knowledge of the ordinary person. Expert evidence on which factors are relevant must be admissible’. 
Secondly, in relation to the admissibility of the decision in question, the Court held that the District Judge did nor err in her reliance upon it.
The District Judge was entitled to receive and admit the findings of the SCA as evidence that M had been recruited and harboured such that he had been trafficked within the meaning of the 2015 Act and that he was a victim of criminal exploitation. The SCA decision maker had expertise in relation to those issues. The judge was entitled to consider the findings and assess the extent to which they were supported by evidence. Insofar as appropriate, she would have been able to reduce the weight she gave to the findings. However, that is a question of weight rather than admissibility. In fact, the SCA decision was based on a proper evidential foundation and it was not contradicted by other material available to the judge. 
It is of note that the DPP sought to argue that if an SCA decision were to be admissible in a criminal trial, in relation to the application of the statutory defence, this would have “significant implications in terms of prosecutorial practice”. Helpfully, the Court rejected this argument, reasoning as follows:
The weight of a conclusive grounds SCA decision will vary. The prosecutor will be in a position to assess the weight of the decision just as the prosecutor can assess the weight of other evidence relevant to the issue of a defendant’s status as a victim of trafficking or exploitation. The decision made by a prosecutor as to whether the defendant has satisfied the evidential burden and, if so, whether the prosecution can disprove the statutory defence will depend on an assessment of all of the available material. 
This decision fills a lacuna in the case law relating to the admissibility of a positive CGD and the basis for it. As a result, this decision is likely to substantially improve the position of child defendants seeking to introduce evidence of criminal exploitation in a prosecution for allegations of criminality arising from it.
Brenda Campbell QC who acted for the respndent comments:
‘The judgment will be of significant value for all defendants who may be victims of modern day slavery. It provides welcome clarity as to the status and admissibility of CGD decisions at trial. However, the weight to be attached to the decision, in the context of s45 defences, remains a matter for the tribunal of fact: they are not bound to accept it. It follows that the more robust the decision, the greater weight that may be attributed to it. For that reason, practitioners should engage with NRM referrals at an early stage, providing as much information / evidence as possible to ensure a positive and well-founded decision.’
Claire Mawer, Barrister, 15 New Bridge Street Chambers