Tactical Non‑Call of a Known Witness Defeats the “Reasonable Explanation” Test for Fresh Evidence Appeals under s 106(3)(a)

1. Introduction

In Appeal against Conviction by Kassim Ashley Green Nicholas against His Majesty's Advocate ([2026] HCJAC 9), the Scottish High Court of Justiciary (Appeal Court) considered an appeal under section 106(3)(a) of the Criminal Procedure (Scotland) Act 1995 (“the 1995 Act”), founded on “fresh evidence” said not to have been heard at trial.

The appellant had been convicted after trial of (i) assault to severe injury of the now deceased Beren McLaughlin and (ii) attempted murder of David Denny by driving a BMW at him and striking him. The appeal ultimately concerned only the second charge.

The proposed fresh evidence was an affidavit from Mr Denny (dated 5 August 2025) asserting that: he had been stabbed by an unidentified person; the appellant did not assault him; and the appellant, as driver, struck him only because Mr Denny ran out in front of the car—after which the driver got out to assist.

A central procedural fact shaped the appeal: at a preliminary hearing (21 March 2024), the defence advised it sought no Crown witnesses for trial. Mr Denny was a listed Crown witness but was not called. Shortly before trial, a soul and conscience certificate indicated that Mr Denny was an inpatient, detained, experiencing a psychotic episode, unfit for court and unlikely to be fit for four weeks. The defence did not move to adjourn the trial.

The key issue became whether there was a “reasonable explanation” (as required by section 106(3A)) for Mr Denny’s evidence not having been led at trial.

2. Summary of the Judgment

The court refused the appeal. It held that the appellant failed to demonstrate a reasonable explanation for the absence of Mr Denny’s evidence at trial.

On the court’s assessment, the defence had made an early and continuing strategic/tactical choice to proceed without Mr Denny—consistent with the trial strategy of putting the Crown to proof on identity of the driver—and had not exhausted reasonable lines of inquiry to obtain or test his evidence (including attempting to trace/precognosce him, seeking to have the Crown cite him, precognoscing him on oath, or moving to adjourn once unfitness was intimated).

Allowing the affidavit to found an appeal would, in substance, permit the appellant to reconstruct his defence post-conviction in a manner contrary to finality and the interests of justice.

3. Analysis

3.1 Precedents Cited

Campbell (T) v HM Advocate 1998 JC 130

The court treated Campbell (T) as the anchor authority on the “reasonable explanation” requirement. It cited the proposition (at p 146F) that the burden lies on the appellant to demonstrate a reasonable explanation for why the evidence was not heard, and that an explanation is not “reasonable” if it is inadequate to account for the omission (p 146G–H).

Applying this, the court examined the defence decisions (including the formal statement that no Crown witnesses were required and the absence of any adjournment motion) and concluded that what was presented did not adequately explain the failure to secure or lead Mr Denny’s account.

Cameron v HM Advocate [2008] HCJAC 39; 2008 SCCR 748

Cameron was relied upon for the principle that an accused cannot, with a view to a later section 106(3)(a) appeal, passively ignore lines of inquiry known (or which ought reasonably to be known) to be of material significance to the defence. The court used this to characterise the appellant’s stance as one of insufficient diligence: Mr Denny was known, listed, and potentially decisive; yet no meaningful inquiry was undertaken to obtain his evidence.

Mills v HM Advocate 1999 JC 216

The court quoted extensively from Mills (p 221E–H) to emphasise the relationship between: (i) the accused’s broad discretion in deploying trial tactics and (ii) the finality of verdicts. Mills explains that an accused cannot elect not to lead a witness for strategic reasons and, following conviction, seek a new trial in order to run a different strategy in the hope of acquittal.

This passage was central to the refusal: the affidavit did not merely supplement the defence case—it pointed to a fundamentally different defence (accepting the appellant as driver and asserting accident/assistance), which conflicted with the trial position that the Crown could not prove he was the driver. The court treated the appeal as an impermissible attempt to re-run the case on a new footing.

Marshall v HMA [2025] HCJAC 20 [59]; 2025 SCCR 235

The court used Marshall as a modern application of the “reasonable explanation” test where the defence made a tactical decision not to seek an adjournment to investigate potentially significant evidence (there, evidence in support of an incrimination). Marshall supported the conclusion that tactical non-adjournment can defeat the reasonable explanation requirement.

By analogy, once the soul and conscience certificate indicated Mr Denny’s unfitness, a defence motion to adjourn (to preserve the opportunity to obtain his evidence) was available. Not taking that step was treated as a deliberate choice consistent with trial tactics, and thus not a “reasonable explanation” for later reliance on his affidavit.

Burzala v HM Advocate [2007] HCJAC 67 [28]; 2008 SLT 61

Burzala was cited (through Marshall) as an example of continued approval of the Mills approach in various contexts. Its role here was confirmatory: the court placed its decision within a stable line of authority resisting post-conviction “tactical reset” litigation.

3.2 Legal Reasoning

1. Statutory gateway: The appeal relied on section 106(3)(a) (miscarriage of justice based on evidence not heard), but section 106(3A) restricts such appeals to cases where there is a reasonable explanation for the evidence not having been led.
2. Known witness, early disclaimer: Mr Denny was known to the defence and listed on the indictment. At the preliminary hearing, the defence formally stated it required no Crown witnesses. The court inferred that this was a deliberate defence stance.
3. Incompatibility with claimed exculpation: If the affidavit’s narrative were true, the appellant would have been aware of the essential facts (being the driver, accidental collision, getting out to help). The court considered it “difficult to understand” how the defence could have regarded Mr Denny as unnecessary if his account truly exculpated the appellant.
4. Failure to exhaust reasonable inquiry: The court identified multiple steps that could reasonably have been taken and were not: attempting to trace/precognosce Mr Denny; requesting the Crown to cite him; precognoscing on oath if necessary; and seeking an adjournment upon receipt of the soul and conscience certificate.
5. Tactical choice and finality: The court accepted the Crown’s submission that proceeding without Mr Denny was likely seen as advantageous to the existing defence strategy (putting the Crown to proof on identity of the driver). Under Mills and Marshall, the law does not permit an appellant to convert such tactical decisions into a later “fresh evidence” miscarriage.
6. Reconstruction rather than reinforcement: The affidavit would not simply strengthen the trial defence; it would replace it with a different defence. The court held that admitting it for that purpose would be “entirely contrary to the interests of justice” and would undermine finality.

3.3 Impact

• Sharper boundary for “fresh evidence” appeals: The decision reinforces that section 106(3A) is a meaningful gatekeeper: appellants must show more than later availability of a helpful statement; they must show a credible and adequate reason why it was not (and could not reasonably have been) led at trial.
• Known witness + tactical silence = high risk on appeal: Where a witness is known and listed, and the defence elects not to pursue them (or not to adjourn to secure them), the court will be slow to accept a later affidavit as “fresh evidence”.
• Diligence expectations on defence preparation: The court’s emphasis on “exhausting all reasonable inquiries” signals that defence teams should document investigative steps (or carefully justified decisions not to take them), especially where a witness could materially affect the narrative on a serious charge.
• Finality and integrity of the trial process: The judgment strengthens the policy that verdicts should not be re-opened simply because a different defence strategy looks attractive after conviction.

4. Complex Concepts Simplified

Section 106(3)(a) appeal (fresh evidence)

An appeal route arguing there was a miscarriage of justice because important evidence was not heard at trial. It is not enough that the evidence is helpful; statutory conditions must be met.

Section 106(3A) “reasonable explanation”

Even if the evidence is new to the court, the appellant must reasonably explain why it was not led at trial. If the defence could reasonably have obtained and led it, the gateway is not satisfied.

Soul and conscience certificate

A medical certificate indicating that a witness (or accused) is not fit to attend court, typically due to health reasons. Here it stated Mr Denny was unfit due to a psychotic episode and unlikely to be fit for weeks.

Precognition / precognosce

A Scottish procedure by which parties take statements or interview witnesses in preparation for trial. The court noted steps could have included attempts to precognosce Mr Denny, including (if necessary) on oath.

Strategic/tactical decision

A deliberate choice about how to run the defence (for example, not calling a witness, or not seeking an adjournment). The court treated such choices as binding in the sense that they cannot ordinarily be undone on appeal by re-litigating with a new plan.

Finality

The principle that criminal verdicts should generally be conclusive to protect both public confidence and the accused from endless litigation. Fresh evidence rules are applied in a way that preserves finality unless strict conditions are met.

5. Conclusion

[2026] HCJAC 9 reaffirms a stringent approach to “fresh evidence” appeals: where a witness is known, listed, and potentially material, an appellant must show that reasonable steps were taken to obtain that evidence for trial—or provide an adequate explanation for not doing so. Tactical choices (including declining to pursue a witness and not seeking adjournment when unfitness is known) will generally defeat the section 106(3A) gateway, particularly where the proposed evidence would enable a wholesale reconstruction of the defence rather than a clarification of the case actually run.