Mutual Corroboration Across Long Intervals and Objective Indecency: Jury Primacy Reaffirmed in HMA v CM [2025] HCJAC 40

Introduction

This appeal under section 107A of the Criminal Procedure (Scotland) Act 1995 concerns the sheriff’s mid-trial decision to uphold a no case to answer submission on a serious sexual charge against a father, CM, alleged to have abused his children in the 1980s and 1990s and, decades later, two teenagers connected to his family. The Crown challenged the sheriff’s ruling on charge 2 (lewd, indecent and libidinous practices against AA when she was between 7 and 11), arguing that there was sufficient corroboration either free-standing or by way of mutual corroboration (the Moorov doctrine) from other charges, notably an indecent assault on his son (charge 4) and later sexual misconduct against teenage girls (charges 6–8).

The core questions were:

Whether the sheriff erred in sustaining a section 97 no case to answer submission by treating mutual corroboration as unavailable due to differences in the character and timing of charges; and
Whether there existed free-standing corroboration on charge 2, independent of mutual corroboration.

The Appeal Court (Lord Justice Clerk Lord Beckett delivering the opinion, with Lord Armstrong and Lady Carmichael concurring) allowed the Crown appeal, reinstating charge 2 and confirming the availability of mutual corroboration across a wide temporal span and differing incidents, subject to jury assessment. The Court took the opportunity to restate important principles on mutual corroboration, the objective test for indecency at common law, and the proper approach to no case to answer submissions.

Summary of the Judgment

The appeal was allowed. The sheriff erred in sustaining the submission of no case to answer on charge 2 (para [42]).
There was free-standing corroboration of charge 2 based on medical/social work evidence and the respondent’s admissions (paras [7]–[11], [41]).
Mutual corroboration was a live jury question between charge 2 (abuse of daughter AA) and charge 4 (indecent assault on son BB with a hammer handle), despite differences and a time gap approaching nine years (paras [39]–[40]).
Sexual gratification is not a necessary element for common law indecent assault; the test is objective, and the complainer’s perception or the accused’s motive is not determinative (paras [39]; citing Somerville, Grainger, and HMA v JSH).
Time gaps, even lengthy ones, do not impose a rule of law requiring “special or compelling” similarities; this is a fact-sensitive jury matter post-Duthie (paras [31], [34]).
At the no case to answer stage, the Crown case must be taken “at its highest” and the “on no possible view” threshold governs; the sheriff erred by engaging in a premature evaluative assessment that is for the jury (paras [29], [36]–[37]).
Practical postscript: judges should utilise the publicly accessible Jury Manual to avoid unnecessary mid-trial appeals; parties share responsibility for having missed free-standing corroboration at first instance; and section 97(2) imposes a clear judicial obligation before acquittal (paras [43]–[44]).

Analysis

1) Precedents Cited and Their Influence

Duthie v HM Advocate [2021] HCJAC 23, 2021 JC 207

Full bench authority removing any rule of law requiring “special, compelling or extraordinary circumstances” to bridge long gaps for mutual corroboration (para [31]).
Overruled CS v HM Advocate (2018) and reframed time gaps as jury questions of fact and degree rather than legal thresholds.
In CM, this underpinned the Court’s conclusion that the sheriff erred by treating long intervals as necessitating exceptional features as a matter of law.

Adam v HM Advocate [2020] HCJAC 5, 2020 JC 141

Important waypoint in the “journey” of mutual corroboration jurisprudence (para [29]).
Reaffirmed the “on no possible view” test at the section 97 stage and recognised the particular context of child sexual abuse (paras [29]–[30]).
CM integrates Adam’s approach but emphasises, via Duthie, that no special rule is imposed by time gaps.

GS v HM Advocate [2023] HCJAC 35, 2024 JC 35

Reiterated that whether there are sufficient similarities in time, character and circumstances is a jury issue unless “impossible” to view the incidents as a single course (para [21]).
Guides CM’s conclusion that the sheriff intruded upon the jury’s province.

HM Advocate v BL [2022] HCJAC 15, 2022 JC 176

Confirms that mutual corroboration can operate between a single incident and a repeated course (para [22]).
Key to rejecting the sheriff’s focus on the isolated nature of charge 4 versus repeated abuse in charge 2.

HM Advocate v JSH [2025] HCJAC 37

Confirms that sexual gratification is not necessary for common law indecent assault; the complainer’s perception or the accused’s motive is not decisive (para [22], [39]).
Central to treating the hammer-handle assault (charge 4) as potentially indecent despite BB’s “punishment” framing.

MR v HM Advocate [2013] HCJAC 8, 2013 JC 212

There is no rule that “the lesser cannot corroborate the greater” (para [32]).
Supports using less serious sexual conduct to corroborate more serious conduct or vice versa.

AS v HM Advocate [2014] HCJAC 135, 2015 SCCR 62; JH v HM Advocate [2022] HCJAC 39, 2023 SCR 26; DW v HM Advocate [2023] HCJAC 28, 2023 SCCR 248

Demonstrate that substantial time gaps (18/19/17 years) do not preclude mutual corroboration (para [34]).
AS frames a “generational interval” analysis; JH and DW reinforce that time is a jury matter and explanations for gaps are not legally required.

Mitchell v HM Advocate [2008] HCJAC 28, 2008 SCCR 469

At the sufficiency stage, the Crown case is taken “at its highest” (para [36]).
CM invokes this to criticise the sheriff’s evaluative approach at section 97.

Somerville v HM Advocate [2010] HCJAC 14, 2010 SCCR 299; Grainger v HM Advocate [2005] HCJAC 11, 2006 JC 141

Somerville: intention/motive is not determinative of indecency (cited at para [39]).
Grainger: indecency is assessed objectively; CM aligns the common law test with section 60 of the 2009 Act’s “reasonable person” sexual test (para [39]).

Taylor v HM Advocate [2019] HCJAC 2, 2019 JC 71; Rysamanowski v HM Advocate [2019] HCJAC 88, 2020 JC 84

Used in CM to explain how corroboration on one charge (e.g., charge 8 via admissions) can provide mutual corroboration for another (charge 7) (para [38]).

Cases cited by the defence: HM Advocate v SM (No 2) [2019] HCJAC 40; RB v HM Advocate [2017] HCJAC 24; RBA v HM Advocate [2019] HCJAC 56

These emphasised stricter similarity/time demands pre-Duthie. CM, attentive to Duthie and later cases, treats the defence’s approach as outdated and inconsistent with contemporary appellate guidance (paras [31], [34]).

2) The Court’s Legal Reasoning

(a) Free-standing corroboration on charge 2

Independent medical/social work materials (admissible via section 259 and Schedule 8) evidenced anal injury, unexplained rectal bleeding and faecal soiling that ceased in residential care (paras [7]–[8]).
The respondent’s own statements, long predating disclosure, suggested knowledge of anal insertion with pegs and pencils, including telling AA’s mother that AA might be using pegs to interfere with herself (para [9]). The Court viewed that observation as “sufficient corroboration of both crime and identification.”
Cumulatively, this was capable of confirming AA’s account of anal penetration with objects and other sexual conduct (para [41]).

(b) Mutual corroboration as a jury question; the “on no possible view” threshold

Mutual corroboration requires the jury to be entitled to infer a single course of conduct persistently pursued by the accused across separate incidents (GS; Adam).
At the section 97 stage, the question is not whether the judge finds the similarities persuasive but whether a jury could on any reasonable view do so; the test is high and rarely met in child sexual abuse cases (paras [29], [37]).
The sheriff erred by conducting a nuanced, evaluative exercise—assessing motive, the isolated nature of charge 4, perceived punishment, and time gaps—instead of leaving those assessments for the jury.

(c) Objective indecency; motive or complainer’s perception is not decisive

Common law indecent assault is judged by an objective test; the accused’s sexual gratification or the complainer’s subjective perception is not determinative (Grainger; Somerville; JSH; para [39]).
On any reasonable view, inserting a hammer handle into a 15-year-old’s anus is indecent; it is for the jury to say so, but the sheriff could not lawfully treat charge 4 as non-sexual to block mutual corroboration (para [39]).

(d) Time intervals, differing ages, and incident patterns

Post-Duthie, there is no legal requirement for “special/compelling” features to bridge time gaps; the jury assesses similarity and unity of purpose (para [31]).
Differing ages (pre-pubescent vs teenager) and incident patterns (course vs single incident) are variations in degree, not legal bars (paras [32]–[33]).
Idiosyncratic features—here, insertion of household objects into the anus of both children in the family home—can supply the requisite link, especially where access and opportunity were intermittent (paras [32], [40]).

(e) Corroborative network across charges 2, 4, 6, 7 and 8

The Court explicitly mapped how charges could cross-corroborate: charge 6 can be corroborated from charges 2, 4, 7 and/or 8; charge 7 from 2, 4 and 6; charge 8 within the same network (para [38]).
Charge 8 enjoyed its own corroboration via admissions about requesting nude images, which could then help corroborate charge 7 (Taylor; Rysamanowski).

(f) Procedural guidance: section 97 and the Jury Manual

Judges must take the Crown case at its highest at the no case to answer stage and must not acquit unless satisfied the evidence is insufficient in law (para [44]).
The Court encouraged primary reliance on the Jury Manual’s up-to-date summaries to avoid mid-trial appeals and delays (para [43]).

3) Likely Impact

On child sexual abuse prosecutions: Reinforces that mutual corroboration can operate across substantial time gaps and generational shifts, especially within families, and that isolated incidents can corroborate courses of conduct. Prosecutors can more confidently present a holistic narrative of persistent offending.
On defence strategy: No case to answer submissions premised on time gaps, lack of sexual motive, or “punishment” framing will carry less weight at the sufficiency stage. The focus will shift to persuading the jury on nuance, not excluding the evidence as a matter of law.
On judicial practice: Firm reminder to refrain from evaluative judgments during section 97 rulings and to consult the Jury Manual. The decision may reduce mid-trial section 107A appeals and associated delays.
On the law of indecency: Consolidates the alignment between the common law objective test for indecent assault and the Sexual Offences (Scotland) Act 2009 section 60 “reasonable person” sexual test, promoting coherence across regimes (para [39]).
On evidential techniques: Validates the evidential importance of admissions and institutional records (admissible hearsay under section 259/Schedule 8) as potential corroboration, particularly in historical abuse cases where forensic evidence is scarce.

Complex Concepts Simplified

Mutual corroboration (often called the Moorov doctrine): When two or more separate offences share similarities in time, character, and circumstances, a jury may infer they are parts of a single course of conduct by the same accused. Each incident can corroborate the others. Post-Duthie, long time gaps do not automatically defeat this; it’s a jury question unless “on no possible view” could the link be drawn.
No case to answer (section 97): A mid-trial defence submission that the Crown evidence is legally insufficient even if taken at its highest. The judge must assume the Crown witnesses are credible and reliable and ask whether a jury could convict. Only if “on no possible view” can the jury find sufficiency should the judge acquit.
Free-standing corroboration: Two independent sources (or one source plus supporting independent facts) confirm essential elements of a specific charge, without relying on cross-charge corroboration.
Objective indecency: For common law indecent assault, the question is whether, viewed objectively, the conduct was indecent. The accused’s motive or the complainer’s perception is not decisive. This dovetails with the 2009 Act’s “reasonable person would regard as sexual” test (section 60).
Section 107A appeal: A mid-trial Crown appeal route against certain rulings (here, sustaining a no case to answer submission) to avoid wrongful acquittals that would stop the trial in its tracks.
Section 259 and Schedule 8 (1995 Act): Provisions permitting certain hearsay and documentary records (e.g., medical or social work records) to be admitted, often crucial in historical abuse allegations.
Generational gap: A period during which the initial child complainers become adults; later allegations may involve younger relatives. This pattern can still support mutual corroboration if the jury sees a continuing course of conduct.
Recently exhibited distress and admissions: Distress shortly after an incident and an accused’s own admissions (including in digital communications) can provide corroboration or support mutual corroboration networks across charges.

Conclusion

HMA v CM [2025] HCJAC 40 is a significant reaffirmation and consolidation of modern Scots law on mutual corroboration and the objective test for indecency. The Court underscores that:

Mutual corroboration is predominantly a jury issue; only where “on no possible view” could the incidents be parts of one course should a judge terminate the case at section 97.
Time gaps—sometimes very long ones—do not impose a special legal test; Duthie governs. Family context and idiosyncratic features (such as anal insertion of household objects) may powerfully support the necessary unity.
Common law indecent assault is assessed objectively; sexual gratification is not required, and the complainer’s description as “punishment” does not strip conduct of its sexual character.
Free-standing corroboration can arise from a robust combination of admissions and institutional records; prosecutors should identify such paths early.

Practically, the decision should reduce premature terminations of sexual cases at the no case to answer stage, encourage careful reliance on the Jury Manual, and promote coherent directions to juries on mutual corroboration and indecency. For the law’s development, CM harmonises earlier strands—Adam and BL—with Duthie’s core message: mutual corroboration across time and circumstance is not an exceptional doctrine but a routine jury inference where a unity of criminal purpose can reasonably be seen.