Recognition of Autism Spectrum Disorder in Sentencing Youth Terrorism Offenders

Introduction

R v Wheeler ([2025] EWCA Crim 558) is a landmark Court of Appeal decision addressing how a diagnosis of Autism Spectrum Disorder (ASD) must inform the sentencing of young offenders in terrorism cases. The applicant, aged 16 at the time of offending and 18 at trial, was convicted of possessing and disseminating terrorist materials in breach of the Terrorism Act 2000 (s.58) and the Terrorism Act 2006 (s.2). Following an extended determinate sentence of six years’ custody and one year’s licence, the applicant appealed on the grounds that his neurological condition—undiagnosed at sentencing—would have led to a materially lower term. The Court of Appeal granted leave to admit fresh psychiatric evidence and allowed the appeal, reducing the custodial term to five years and rescinding the licence extension.

Summary of the Judgment

The Court of Appeal reaffirmed that fresh evidence under section 23 of the Criminal Appeal Act 1968 was admissible, then considered two new expert reports diagnosing the applicant with high-functioning ASD. Although the sentencing judge had been aware of autistic traits from an earlier report, she did not have a formal diagnosis or detailed analysis of how ASD affects emotional expression and the perception of maturity or dangerousness. The Appeal Court held that, absent the judge’s comments on the applicant’s “cold and calculating” courtroom demeanour—now understood as a feature of ASD—the appropriate reduction from the adult sentence should have been greater. By crediting the new evidence, the Court reduced the custodial term from six to five years and rescinded the one-year extended licence period, while preserving notification requirements.

Analysis

Precedents Cited

• Gafoor [2002] EWCA Crim 1857 and Bowker [2007] EWCA Crim 1608: established principles for adjusting adult sentences to reflect youth; referred to when calibrating sentencing reductions for a 16-year-old offender.
• ZA [2023] EWCA Crim 516: applied the Sentencing Council’s Young Offenders guideline, confirming that reductions of one-third to one-half are appropriate for serious offences committed by children.
• Sentencing Council guidelines for Children and Young People: highlight maturity, emotional development and vulnerability factors that must be weighed when sentencing under-18 offenders.
• Section 23, Criminal Appeal Act 1968: governs admission of fresh evidence on appeal; the Court found the two new psychiatric reports met the statutory criteria for believability, potential to afford a ground of appeal, admissibility and reasonable explanation for late submission.

Legal Reasoning

The Court’s reasoning unfolded in four stages:

1. Admissibility of fresh evidence: The reports by Dr Samuel Yates and Dr Robert Halsey were credible, relevant to sentencing and could not have been obtained earlier. The Court granted leave under s.23 CAA 1968.
2. Effect of ASD on sentencing reductions: The sentencing judge’s principal basis for a 25% reduction was the applicant’s perceived maturity and controlled presentation. The new evidence showed that a “flat” emotional affect is a core ASD trait, not an indicator of calculated intent. This misunderstanding led to an insufficient youth discount.
3. Reassessment of dangerousness: Dangerousness under s.266 Sentencing Act 2020 requires a personal risk assessment. The judge had partially relied on the applicant’s courtroom demeanour to find “cold and calculating” risk. With the ASD evidence, that finding was no longer sustainable.
4. Substitution of sentence: Absent the mischaracterisation of ASD-related behaviours, an adult starting point of eight years warranted a greater youth reduction. The Court substituted five years’ detention and removed the extended licence, while leaving the 15-year notification duty intact.

Impact

This decision establishes crucial guidance for future cases:

• Sentencing judges must investigate and properly understand neurodivergent conditions when evaluating maturity, remorse and dangerousness.
• Psychiatric or psychological evidence relating to ASD cannot be discounted as peripheral; it may materially affect both culpability and the appropriate youth discount.
• Appellate courts will admit fresh expert evidence on neurological conditions where it could alter the sentencing exercise, promoting procedural fairness for vulnerable offenders.
• In terrorism sentencing, presentations of coldness or emotional detachment must be distinguished from calculated intent: failure to do so risks over-punishment.

Complex Concepts Simplified

Extended Determinate Sentence

A custodial term combining a fixed period in custody and a later licence period. It addresses both punishment and public protection when an offender is deemed dangerous.

Dangerousness (Sentencing Act 2020, s.266)

A statutory finding that the offender poses a significant risk of serious harm to the public if not subject to extended supervision.

Autism Spectrum Disorder (ASD)

A neurodevelopmental condition affecting social interaction, communication and emotional processing; traits may include flat affect, repetitive behaviors and intense interests.

Fresh Evidence (Criminal Appeal Act 1968, s.23)

Evidence not available at trial which can be admitted on appeal if it is credible, would have been admissible originally, and might have affected the outcome.

Conclusion

R v Wheeler marks a significant evolution in sentencing jurisprudence: it compels judges to fully consider neurodevelopmental diagnoses—particularly ASD—when assessing the maturity, culpability and dangerousness of young offenders. By admitting fresh evidence and recalibrating the youth discount, the Court of Appeal reaffirmed the principle that sentencing must account for an offender’s neurological profile. This judgment will guide future courts in balancing public protection against the rights and vulnerabilities of neurodivergent individuals, ensuring just and proportionate outcomes.