An extended sentence of detention in a young offender institution is available in respect of an offence where—
The pre-sentence report requirements (see section 30) apply to the court in relation to forming the opinion mentioned in subsection (1)(c).
The earlier offence condition is that, when the offence was committed, the offender had been convicted of an offence listed in Part 1, 2 or 3 of Schedule 14.
But if the proceedings for the offence were instituted before IP completion day (see section 397(5)), the earlier offence condition is that, when the offence was committed, the offender had been convicted of an offence listed in Part 1, 2, 3 or 3A of Schedule 14.
The 4 year term condition is that, if the court were to impose an extended sentence, the term that it would specify as the appropriate custodial term (see section 268) would be at least 4 years.