“Re-calibrating Indefinite Detention” – The Preference for Extended Sentences over IPP for Young Dangerous Offenders

Commentary on Sillitto, R. v ([2025] EWCA Crim 868), Court of Appeal (Criminal Division), 17 June 2025

1. Introduction

In Sillitto the Court of Appeal (Criminal Division) re-examined the proper sentencing response to grave but non-penetrative sexual offending committed by a 19-year-old first-time prisoner. Sentenced in 2012 to an indefinite sentence of detention for public protection (IPP), Sillitto had served more than eleven years when fresh counsel obtained leave to appeal out of time. The appellate court quashed the IPP and substituted an extended sentence of nine years (six years’ custody plus three years’ extended licence) together with a robust Sexual Offences Prevention Order (SOPO).

The judgment provides an authoritative restatement—bordering on a new benchmark—of the principle that IPP/indefinite detention is the “last-but-one” resort, to be imposed only where an extended sentence, bolstered by ancillary orders, cannot adequately protect the public. It is especially salient for young dangerous offenders whose maturity trajectory and lack of previous convictions render future risk inherently fluid.

2. Summary of the Judgment

• The Court confirmed that, although Sillitto’s offending was “very serious, and very troubling,” the Recorder erred in principle by imposing an IPP without demonstrating why an extended sentence would be insufficient.
• Emphasis was placed on the offender’s youth, limited criminal history, and the availability of licence supervision plus a tailor-made SOPO to manage ongoing risk.
• The IPP was therefore quashed; an extended sentence under s.227 Criminal Justice Act 2003 of nine years (custodial term six years + extension period three years) was substituted.
• The original SOPO was replaced by a more comprehensive, time-limited SOPO containing detailed prohibitions on internet use, contact with females and children, and association with other sex offenders.

3. Analysis

3.1 Precedents Cited and Their Influence

1. Attorney-General’s Reference No. 55 of 2008 (R v C and others) [2009] 2 Cr App R(S) 22
   Re-affirmed that IPP is “the last but one resort” and should give way to an extended sentence where the latter affords adequate protection. The Court imported this dictum wholesale, treating it as a controlling statement.
2. R v Roberts [2016] 1 WLR 3249
   This authority delineates the appellate function as one of review—not resentencing—so the Court framed the critical question: Was the IPP wrong in principle given the information before the Recorder? Roberts thus limited hindsight-based arguments and kept the focus on material available at the 2012 sentencing hearing.

Practical effect: By integrating these precedents, the Court clarified that “dangerousness” findings do not automatically equate to IPP; sentencers must evidence why lesser measures cannot mitigate risk.

3.2 Legal Reasoning

• Youth & Potential for Maturation: At 19, the appellant’s personality and decision-making capacities were still developing. Maturation, exposure to structured custodial programmes, and post-release supervision were all factors likely to reduce risk.
• Risk-versus-Facts Misalignment: The Recorder focused heavily on the disturbing factual narrative rather than on future risk management. The Court of Appeal insisted that sentencing for dangerousness requires a prospective assessment.
• Adequacy of Ancillary Orders: Because modern SOPOs (now SHPOs) and Sex Offender Notification requirements impose rigorous controls, they can significantly neutralise residual risk, tipping the balance against IPP.
• Discretion under s.225 vs s.227 CJA 2003: Under the statutory regime then in force, an extended sentence was plainly available once (a) the notional custodial term exceeded four years and (b) dangerousness was found. The Court held that the Recorder’s failure to justify departure from that statutory alternative constituted error.

3.3 Impact of the Decision

This judgment is poised to influence sentencing and appellate practice in three salient ways:

1. Guidance for Historic IPP Cases: Offenders sentenced pre-LASPO who are still incarcerated may invoke Sillitto to argue that a lesser but protective regime would have sufficed at the time of sentencing.
2. Youth-Centric Risk Assessment: Trial judges must now expressly address the maturation potential of late-teen offenders when weighing IPP against extended sentences.
3. Enhanced Reliance on Ancillary Orders: The Court’s willingness to craft a detailed SOPO underscores their centrality in risk mitigation, likely prompting more creative and stringent use of post-release restrictions.

4. Complex Concepts Simplified

• IPP (Imprisonment for Public Protection): An open-ended sentence where release depends on Parole Board assessment; licence lasts for life.
• Extended Sentence (s.227 CJA 2003): A fixed custodial term plus an extended licence (up to five years for sexual offences; now up to eight under LASPO). The offender is automatically released at the two-thirds point (post-2020) or halfway point (pre-2020) unless the Parole Board blocks release, and supervision ends when the extended period lapses.
• SOPO / SHPO: Court orders imposing tailored behavioural restrictions to protect the public from sexual harm; breach is a criminal offence punishable by up to five years’ imprisonment.
• Dangerousness Finding: A statutory test (then s.229 CJA 2003) requiring the court to decide if there is a “significant risk” of “serious harm” from future offences.

5. Conclusion

Sillitto firmly re-asserts that indefinite detention must remain exceptional. Sentencers must conduct a granular, forward-looking risk analysis that factors in youth, personal development, treatment prospects, and the protective force of licence conditions and ancillary orders. Where those mechanisms suffice, an extended sentence—not IPP—should be imposed.

In the wider legal landscape, the decision offers a lifeline to still-incarcerated IPP prisoners, encourages courts to harness sophisticated SOPO/SHPO drafting, and recalibrates the balance between public safety and proportional sentencing for young dangerous offenders.