“…an offence is associated with another if (a) the offender is convicted of it in proceedings in which he is convicted of the other offence, or (although convicted of it in earlier proceedings, is sentenced for it at the same time as he is sentenced for that offence) or (b) the offender admits the commission of it in the proceedings in which he is sentenced for the other offence and requests the court to take it into considering when sentencing him for that offence.”
“(1) This section applies where (a) a person aged 18 or over is convicted of a specified offence committed after the commencement of this section, and (b) the court considers that there is a significant risk to members of the public of serious harm occasioned by the commission by the offender of further specified offences, but (c) the court is not required by section 225(2) to impose a sentence of imprisonment for life or, in the case of a person aged at least 18 but under 21, a sentence of custody for life.” (2) The court may impose on the offender an extended sentence of imprisonment or, in the case of a person aged at least 18 but under 21, an extended sentence of detention in a young offender institution if the condition in sub-section (2A) or the condition in sub-section (2B) is met. (2A) The condition in this sub-section is that, at the time when the offence was committed, the offender had been convicted in any part of the United Kingdom of an offence specified in schedule 15A (2B) The condition in this sub-section is that, if the court were to impose an extended sentence of imprisonment, the term or in the case of an offender aged at least 18 but under 21, an extended sentence of detention in a young offender institution, it would specify as the appropriate custodial term would be at least 4 years. (2C) An extended sentence of imprisonment or, in the case of an offender aged at least 18 but under 21, an extended sentence of detention in a young offender institution is a sentence of imprisonment or detention in a young offender institution the term of which is equal to the aggregate of (d) The appropriate custodial term, and (e) A further period (“the extension period”) for which the offender is to be subject to a licence and is of such length as the court considers necessary for the purpose of protecting members of the public from serious harm occasioned by the commission by him of further specified offences….”