Establishing the Credibility Threshold for Section 45 Defences and Fresh Evidence Admissibility in Criminal Appeals

Introduction

R. v BKM [2025] EWCA Crim 389 concerns BKM’s appeal from convictions for possession of a bladed article and two counts of possession of a Class A drug with intent to supply. BKM pleaded guilty on his trial day before the Crown Court at Southwark, received concurrent two-year sentences for the drug counts and a consecutive two-month term for the knife. Nearly five years later he sought (1) an extension of time and leave to appeal against conviction on grounds that the Crown Prosecution Service (CPS) failed to apply its trafficking guidance and (2) an appeal against sentence, arguing he might have advanced a Modern Slavery Act 2015 s 45 defence. The Court of Appeal refused both, setting out detailed reasons on the admissibility of fresh evidence, the assessment of credibility, and the legal test for s 45 defences in post-conviction proceedings.

Summary of the Judgment

The Court of Appeal, led by Lord Justice Davis, dismissed BKM’s applications:

On conviction: Even if CPS guidance on trafficking had been ignored, and fresh evidence (positive Single Competent Authority decisions and witness statements) was admitted for argument, BKM’s account of compulsion failed the credibility test. His inconsistent statements and implausible narrative meant no reasonable jury would have accepted a s 45 defence or declined prosecution on public interest grounds.
On sentence: The original custodial terms were lenient, the plea reduction generous, and BKM’s trafficking status bore no real connection to the offending. No arguable ground existed to interfere with sentence.

Analysis

1. Precedents Cited

ARU [2023] EWCA Crim 23 ([99]): Established a four-step checklist for post-guilty-plea appeals when a defendant alleges improper advice on a s 45 defence:
1. Should the defendant have been advised of the s 45 defence?
2. Was such advice given?
3. Had advice been given, was it open to him to raise the defence?
4. Were the prospects of its success good?
AAD [2022] EWCA Crim 106 ([82]–[83]): Confirmed that while an SCA conclusive grounds decision is not binding, absent contradictions or manifest flaws it commands respect; if challenged, the court may require oral evidence to test credibility.
Criminal Appeal Act 1968, s 23(2): Governs the test for allowing fresh evidence—whether it may “afford any grounds for allowing the appeal.”

2. Legal Reasoning

The court’s reasoning unfolded in two stages:

Admissibility and Weight of Fresh Evidence: The applicant sought to rely on two positive SCA decisions (reasonable grounds and conclusive grounds) plus witness statements recounting his trafficking and coerced involvement in drugs. The court admitted this evidence de bene esse (for argument’s sake) but subjected it to rigorous scrutiny. It noted the SCA failed to address material inconsistencies between accounts, downplayed discrepancies without explanation, and therefore could not be taken at face value.
Credibility Assessment and Impact on Appeal: Central to the decision was Lord Justice Davis’s detailed credibility analysis of BKM’s narrative on 24 April 2018. The court found his claim of compulsion implausible given his ability to resist, disarm, pursue, and then inexplicably dispose of weapons and drugs. These findings foreclosed any realistic prospect that a jury—properly directed on s 45—would have accepted a trafficking-based duress defence or declined prosecution. Accordingly, neither conviction nor sentence review could succeed.

3. Impact on Future Cases

This decision clarifies several points for practitioners and lower courts:

Fresh evidence from SCA decisions must be critically examined for internal consistency; the court will not automatically adopt favorable findings without scrutiny.
The ARU checklist remains authoritative for post-plea appeals asserting s 45 defences, but prospects of success hinge on realistic, coherent evidence that could persuade a jury.
Credibility remains the linchpin: an appellant’s own inconsistent accounts can fatally undermine trafficking or compulsion defences.
The CPS guidance on victims of trafficking does not, by itself, prevent prosecution: public interest and evidential sufficiency remain paramount.

Complex Concepts Simplified

Section 45 Defence (Modern Slavery Act 2015): A statutory defence allowing a person compelled to commit an offence through slavery, servitude, or relevant exploitation to argue non-criminality.
Single Competent Authority (SCA): A Home Office body determining whether an individual is a trafficking victim. “Reasonable grounds” is a preliminary positive finding; “conclusive grounds” confirms victim status.
De bene esse: Latin for “provisionally”; evidence admitted “just in case” it becomes necessary, without final ruling on its admissibility.
Merton‐compliant age assessment: A standardized procedure to determine if an asylum seeker is a minor, triggering special legal protections.
Abuse of Process: A doctrine allowing courts to stay prosecutions when continuance would be unfair or an affront to justice (e.g., ignoring trafficking status).

Conclusion

R. v BKM reaffirms the rigorous standards governing post-conviction challenges based on trafficking and modern slavery defences. The Court of Appeal underscored that:

Fresh evidence from trafficking decisions must be coherent and withstand adversarial testing.
Credibility is decisive; inconsistent narratives will defeat both convictions and defence claims under s 45.
The ARU checklist guides s 45 advice-and-prospect-of-success assessments, but speculative or implausible accounts cannot revive later appeals.

This precedent thus provides definitive guidance on the interplay between CPS trafficking obligations, SCA findings, and the scope of modern slavery defences in criminal appeals.