Children and Young People Guideline Must Inform Sentencing for Terrorism Information Offences Committed Under 18 (Even if Sentenced as an Adult)

1. Introduction

This was an Attorney General’s Reference contending that a sentence imposed for four offences of collecting terrorist information (contrary to s.58 Terrorism Act 2000) was unduly lenient. The respondent (a young adult at sentence) had committed part of the offending while under 18, with some conduct continuing briefly after turning 18.

The key issues were:

• Guideline framework: how the offence-specific guideline for adult s.58 offending should be applied alongside the Overarching Guideline on Sentencing Children and Young People where the offender was a child at the time of (at least some) offending.
• Categorisation: whether the offences fell into Category B2 (as ultimately agreed), and the significance of the judge’s initial B3 categorisation and later “slip rule” clarification.
• Appellate restraint on Attorney General References: whether a community order, albeit “lenient”, crossed the high threshold of being unduly lenient.

2. Summary of the Judgment

The Court of Appeal:

• Granted leave to consider the reference (given the categorisation history), but
• Refused the reference, holding that although the sentence was lenient, it was not unduly lenient.

The court accepted that the offences were properly treated as Category B2 under the adult offence-specific guideline (starting point 4 years), but held that the sentencing judge was required (and entitled) to apply the children/young people overarching guideline to the extent the offending was committed under 18, and to treat “18” as not a cliff edge. Taking into account youth, immaturity, and psychiatric evidence, the community-based disposal fell within the judge’s lawful discretion.

3. Analysis

3.1 Precedents Cited

R v Ahmed [2023] EWCA Crim 281; [2023] 1 WLR 1858

This was the decisive authority on the applicability of the children/young people guideline when the offender is sentenced as an adult for offences committed as a child. The court quoted and applied the key proposition:

In Shafiq, no party contended that applying the children guideline would be “contrary to the interests of justice”. The Attorney General’s refined argument was essentially that even applying that guideline, only immediate custody was adequate for terrorism-related s.58 offending. The court rejected that as a universal rule and treated Ahmed as requiring structured consideration of the child-sentencing principles in the overall calculus.

R v Bel [2021] EWCA Crim 1461

This case was referred to by the sentencing judge in relation to harm assessment—distinguishing between objective and subjective elements in evaluating harm/risk in terrorism information cases. While the appellate judgment did not elaborate extensively, it treated the judge’s approach as within the permissible evaluative space when determining how the guideline’s harm descriptors applied to the facts.

3.2 Legal Reasoning

(a) Correct guideline category and the “slip rule”

The court accepted that the sentencing judge initially mis-stated the category as B3, later clarified to B2. Importantly, the court noted the overlap between B2 and B3 ranges (including the same upper limit), reducing the practical significance of the initial error. The core question remained whether, after proper categorisation, the judge’s ultimate disposal was outside the reasonable sentencing bracket.

(b) Interaction between the adult terrorism guideline and the children/young people guideline

The court treated the sentencing exercise as “nuanced” because:

• some offending occurred when the offender was under 18;
• some conduct continued beyond 18; and
• sentence was imposed when the offender was over 18.

Applying R v Ahmed, the court held the children/young people guideline was not optional. It also endorsed the broader principle that “18 is not a cliff edge”—meaning developmental factors relevant before 18 may remain pertinent shortly after. Accordingly, the court accepted the judge’s reliance on youth justice aims (preventing offending; welfare) as part of the overall proportionality analysis, even in a terrorism context.

(c) Mitigation and culpability reduction

The court considered it was open to the judge to treat the respondent’s:

• youth and immaturity,
• previous good character,
• compliance while on bail, and
• psychiatric evidence indicating traits consistent with Asperger’s syndrome (as described in the report)

as materially affecting culpability and the appropriate disposal. The court noted the sentencing judge nonetheless found “ample evidence” from the digital material consistent with terrorist motivations, so this was not a case where culpability was reduced because the conduct was treated as benign or merely accidental. Rather, mitigation drove the judge’s conclusion that public protection and rehabilitation could best be achieved via a community order plus restrictive ancillary measures.

(d) Attorney General Reference threshold: “lenient” vs “unduly lenient”

The Court of Appeal reiterated the familiar constraints of the Attorney General Reference jurisdiction: the sentencing judge is usually best placed to assess factors, and the jurisdiction corrects gross sentencing error rather than mere disagreement. On that basis, the court held the community order fell within the wide ambit of reasonable outcomes in this unusual age/immaturity context, even though the court itself considered it “lenient”.

3.3 Impact

• Reinforcement of mandatory relevance of the children guideline: Shafiq confirms in terrorism sentencing that R v Ahmed applies with full force—where offending was committed under 18, the children/young people guideline must be followed unless “interests of justice” displace it.
• Practical handling of “straddling 18” offending: the decision recognises the reality of offending that begins before 18 and continues shortly after, and supports a blended assessment rather than a rigid adult-only approach.
• Limits of appellate intervention: even in terrorism-related offending with an adult guideline starting point measured in years, a non-custodial sentence will not necessarily be “unduly lenient” where the judge has demonstrably engaged with the correct frameworks and evidence.
• Supervision and protective structure matter: the court’s recital of intensive post-sentence monitoring indicates that, when assessing appropriateness of community disposals in high-risk categories, the practical machinery of control/rehabilitation may be relevant to evaluating the rationality of the sentencing choice.

4. Complex Concepts Simplified

• Section 58 Terrorism Act 2000 (collection of terrorist information): criminalises collecting/possessing/viewing information likely to be useful for terrorism. “Information” includes digital publications and instructional material.
• Culpability and harm categories (B2 etc.): sentencing guidelines often use grids. “Culpability” reflects blameworthiness (e.g., motivations, planning). “Harm” reflects the risk/seriousness inherent in the material and likelihood of harm.
• Totality: when sentencing multiple offences, the court ensures the overall sentence is proportionate to the total criminality, not a simple arithmetic sum.
• Slip rule: a limited power allowing the court to correct accidental errors in orders/records. Here it was used to clarify the intended guideline category.
• Attorney General’s Reference (s.36 Criminal Justice Act 1988): a mechanism to challenge sentences as “unduly lenient”. The threshold is high: the sentence must be outside the range a judge could reasonably impose.
• Overarching Guideline on Sentencing Children and Young People: requires focus on preventing offending and promoting welfare when the offender was under 18 at guilt (and, per R v Ahmed, remains relevant for offences committed under 18 even if sentenced later as an adult, unless interests of justice require otherwise).

5. Conclusion

[2026] EWCA Crim 921 is a guideline-application case of real practical importance: it confirms that when terrorism-related offending under s.58 is committed while the offender is under 18, sentencers must integrate the children/young people sentencing framework even if sentence is passed in adulthood and even where the adult offence guideline points to years of custody. The Court of Appeal’s refusal of the Attorney General’s Reference underlines both (i) the continued legal force of R v Ahmed and the “not a cliff edge” approach to turning 18, and (ii) the strict limits of “unduly lenient” review where the sentencing judge has conscientiously applied the correct legal principles to an unusual personal and evidential matrix.