Commentary First Group of Parts – Discipline Part 8 – Sentencing Powers and Mandatory Etc Sentences Section 218: Offenders who commit murder etc when under 18: mandatory detention at Her Majesty’s pleasure
443.Where life imprisonment is mandatory in the case of the corresponding civilian offence but the offender was under 18 at the time of the offence, under this section the court must sentence him to be detained during Her Majesty’s pleasure.